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Sample records for tendons structural

  1. Containment structure tendon investigation

    International Nuclear Information System (INIS)

    Fulton, J.F.; Murray, K.H.

    1983-01-01

    The paper describes an investigation into the possible causes of lower-than-predicted tendon forces which were measured during past tendon surveillances for a concrete containment. The containment is post tensioned by vertical tendons which are anchored into a rock foundation. The tendons were originally stressed in 1969, and lift-off tests were performed on six occasions subsequent to this date over a period of 11 years. The tendon forces measured in these tests were generally lower than predicted, and by 1979 the prestress level in the containment was only marginally above the design requirement. The tendons were retensioned in 1980, and by this time an investigation into the possible causes was underway. Potential causes investigated include the rock anchors and surrounding rock, elastomeric pad creep, wire stresses, thermal effects, stressing equipment and lift-off procedures, and wire stress relaxation. The investigation activities included stress relaxation testing of wires pulled from actual tendons. The stress relaxation test program included wire specimens at several different temperature and initial stress levels and the effect of a varying temperature history on the stress relaxation property of the wires. For purpose of future force predictions of the retensioned tendons, the test program included tests to determine the effect on stress relaxation due to restressing the wires after they had relaxed for 1000 hours and 10,000 hours. (orig./GL)

  2. Structural tendon changes in patients with acromegaly: assessment of Achilles tendon with sonoelastography.

    Science.gov (United States)

    Onal, Eda Demil; Ipek, Ali; Evranos, Berna; Idilman, Ilkay Sedakat; Cakir, Bekir; Ersoy, Reyhan

    2016-03-01

    To describe the sonoelastographic appearance of the Achilles tendon in acromegalic patients and to determine whether the blood concentrations of growth hormone (GH) and insulin-like growth factor (IGF-1) are associated with the various sonographic elasticity types of Achilles tendons. Eighty-four Achilles tendons of 42 acromegaly patients and 84 Achilles tendons of 42 healthy volunteers were assessed with sonoelastography. The tendons were classified into two main types according to the elasticity features: type 1 blue/green (hard tissue) and type 2 yellow/red within green (intermediate-soft tissue). Two subtypes of these types were also defined. According to the definition, the elasticity of the tissue was in a spectrum ranging from hard to soft as the type progressed from 1a to 2b. The mean thickness of Achilles tendons in patients with acromegaly was significantly higher compared with healthy Achilles tendons (5.1+/-0.7 mm vs. 4.4+/-0.5, pacromegaly patients had type 2 sonoelastographic appearance of the Achilles tendon (124/252 third; 49.2% vs. 81/252 third; 32.1%, p=0.0001). Activity status of acromegaly and GH/IGF-I levels were similar in patients with different types of elasticity (p>0.05). Sonoelastography revealed structural changes in the tendinous tissue of patients with acromegaly, but it was not sensitive enough to reflect changes in the serum levels of GH/IGF-1.

  3. 77 FR 69508 - Inservice Inspection of Prestressed Concrete Containment Structures With Grouted Tendons

    Science.gov (United States)

    2012-11-19

    ... Containment Structures With Grouted Tendons AGENCY: Nuclear Regulatory Commission. ACTION: Regulatory guide... (RG) 1.90, ``Inservice Inspection of Prestressed Concrete Containment Structures with Grouted Tendons... appropriate surveillance program for prestressed concrete containment structures with grouted tendons...

  4. Numerical models for prestressing tendons in containment structures

    International Nuclear Information System (INIS)

    Kwak, Hyo-Gyoung; Kim, Jae Hong

    2006-01-01

    Two modified stress-strain relations for bonded and unbonded internal tendons are proposed. The proposed relations can simulate the post-cracking behavior and tension stiffening effect in prestressed concrete containment structures. In the case of the bonded tendon, tensile forces between adjacent cracks are transmitted from a bonded tendon to concrete by bond forces. Therefore, the constitutive law of a bonded tendon stiffened by grout needs to be determined from the bond-slip relationship. On the other hand, a stress increase beyond the effective prestress in an unbonded tendon is not section-dependent but member-dependent. It means that the tendon stress unequivocally represents a uniform distribution along the length when the friction loss is excluded. Thus, using a strain reduction factor, the modified stress-strain curve of an unbonded tendon is derived by successive iterations. In advance, the prediction of cracking behavior and ultimate resisting capacity of prestressed concrete containment structures using the introduced numerical models are succeeded, and the need for the consideration of many influencing factors such as the tension stiffening effect, plastic hinge length and modification of stress-strain relation of tendon is emphasized. Finally, the developed numerical models are applied to prestressed concrete containment structures to verify the efficiency and applicability in simulating the structural behavior with bonded and/or unbonded tendons

  5. Structured white light scanning of rabbit Achilles tendon.

    Science.gov (United States)

    Hayes, Alex; Easton, Katrina; Devanaboyina, Pavan Teja; Wu, Jian-Ping; Kirk, Thomas Brett; Lloyd, David

    2016-11-07

    The cross-sectional area (CSA) of a material is used to calculate stress under load. The mechanical behaviour of soft tissue is of clinical interest in the management of injury; however, measuring CSA of soft tissue is challenging as samples are geometrically irregular and may deform during measurement. This study presents a simple method, using structured light scanning (SLS), to acquire a 3D model of rabbit Achilles tendon in vitro for measuring CSA of a tendon. The Artec Spider™ 3D scanner uses structured light and stereophotogrammetry technologies to acquire shape data and reconstruct a 3D model of an object. In this study, the 3D scanner was integrated with a custom mechanical rig, permitting 360-degree acquisition of the morphology of six New Zealand White rabbit Achilles tendons. The reconstructed 3D model was then used to measure CSA of the tendon. SLS, together with callipers and micro-CT, was used to measure CSA of objects with a regular or complex shape, such as a drill flute and human cervical vertebra, for validating the accuracy and repeatability of the technique. CSA of six tendons was measured with a coefficient of variation of less than 2%. The mean CSA was 9.9±1.0mm 2 , comparable with those reported by other researchers. Scanning of phantoms demonstrated similar results to μCT. The technique developed in this study offers a simple and accurate method for effectively measuring CSA of soft tissue such as tendons. This allows for localised calculation of stress along the length, assisting in the understanding of the function, injury mechanisms and rehabilitation of tissue. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Effect of estrogen on tendon collagen synthesis, tendon structural characteristics, and biomechanical properties in postmenopausal women

    DEFF Research Database (Denmark)

    Hansen, Mette; Kongsgaard, Mads; Holm, Lars

    2009-01-01

    and fibril characteristics were determined by MRI and transmission electron microscopy, whereas tendon biomechanical properties were measured during isometric maximal voluntary contraction by ultrasound recording. Tendon FSR was markedly higher in ERT-users (P

  7. Calf Endurance and Achilles Tendon Structure in Classical Ballet Dancers.

    Science.gov (United States)

    Zellers, Jennifer A; van Ostrand, Katrina; Silbernagel, Karin Grävare

    2017-06-15

    Optimal lower leg function is critical for ballet dancers to meet their occupational requirements. Achilles tendon injury is particularly detrimental to ballet dancers. While standardized measures have been validated and incorporated into clinical practice for use in people with Achilles tendon injury, normative ranges specific to the dancer population have not been described. The purpose of this pilot study was to observe the performance of pre-professional ballet students and professional ballet dancers on a well-established test battery for lower leg functional performance as well as ultra-sonographic evaluation of the structure of their Achilles tendons. The dancers in this study had significantly shorter Achilles tendons than non-dancers (p = 0.016). Dancers demonstrated significantly higher maximum heel-rise height on the heel-rise test for calf endurance (p < 0.001) but performed significantly less work than non-dancers (p = 0.014). The results of this study support the use of the heel-rise test as a tool for screening and to guide rehabilitation.

  8. Generalization of proposed tendon friction correlation and its application to PCCV structural analysis

    International Nuclear Information System (INIS)

    Kashiwase, Takako; Nagasaka, Hideo

    2000-01-01

    The present paper dealt with the extension of tendon friction coefficient correlation as a function of loading end load and circumferential angle, proposed in the former paper. The extended correlation further included the effects of the number of strands contacted with sheath, tendon diameter, politicization of tendon and tendon local curvature. The validity of the correlation was confirmed by several published measured data. The structural analysis of middle cylinder part of 1/4 PCCV (Prestressed Concrete Containment Vessel) model was conducted using the present friction coefficient correlation. The results were compared with the analysis using constant friction coefficient, focused on the tendon tension force distribution. (author)

  9. FRP tendon anchorage in post-tensioned concrete structures

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Täljsten, Björn; Bennitz, Anders

    2008-01-01

    effective Young´s modulus and the high stress capacity in the linear elastic range of the material. The use of external tendons increases the requirements on the anchorage systems. This is in particular important when using un-bonded tendon systems, where the anchorage and deviators are the only force...... transfer points. The demand for high capacity anchorage tendons is fulfilled for steel tendons, but no competitive mechanical anchor has yet been developed for FRP tendon. A new small, reliable and more user friendly anchor has to be developed, before FRP tendons can be utilized with all of its capacity...

  10. Structural model testing for prestressed concrete pressure vessels: a study of grouted vs nongrouted posttensioned prestressing tendon systems

    International Nuclear Information System (INIS)

    Naus, D.J.

    1979-04-01

    Nongrouted tendons are predominantly used in this country as the prestressing system for prestressed concrete pressure vessels (PCPVs) because they are more easily surveyed to detect reductions in prestressing level and distress such as results from corrosion. Grouted tendon systems, however, offer advantages which may make them cost-effective for PCPV applications. Literature was reviewed to (1) provide insight on the behavior of grouted tendon system, (2) establish performance histories for structures utilizing grouted tendons, (3) examine corrosion protection procedures for prestressing tendons, (4) identify arguments for and against using grouted tendons, and (5) aid in the development of the experimental investigation. The experimental investigation was divided into four phases: (1) grouted-nongrouted tendon behavior, (2) evaluation of selected new material systems, (3) bench-scale corrosion studies, and (4) preliminary evaluation of acoustic emission techniques for monitoring grouted tendons in PCPVs. The groutability of large tendon systems was also investigated

  11. Effect of prostaglandin E2 injection on the structural properties of the rat patellar tendon

    Directory of Open Access Journals (Sweden)

    Ferry Scott T

    2012-01-01

    Full Text Available Abstract Background Increased tendon production of the inflammatory mediator prostaglandin E2 (PGE2 has been suggested to be a potential etiologic agent in the development of tendinopathy. Repeated injection of PGE2 into tendon has been proposed as a potential animal model for studying treatments for tendinopathy. In contrast, nonsteroidal anti-inflammatory drugs (NSAIDs which inhibit PGE2 production and are commonly prescribed in treating tendinopathy have been shown to impair the healing of tendon after acute injury in animal models. The contradictory literature suggests the need to better define the functional effects of PGE2 on tendon. Our objective was to characterize the effects of PGE2 injection on the biomechanical and biochemical properties of tendon and the activity of the animals. Our hypothesis was that weekly PGE2 injection to the rat patellar tendon would lead to inferior biomechanical properties. Methods Forty rats were divided equally into four groups. Three groups were followed for 4 weeks with the following peritendinous injection procedures: No injection (control, 4 weekly injections of saline (saline, 4 weekly injections of 800 ng PGE2 (PGE2-4 wks. The fourth group received 4 weekly injections of 800 ng PGE2 initially and was followed for a total of 8 weeks. All animals were injected bilaterally. The main outcome measurements included: the structural and material properties of the patellar tendon under tensile loading to failure, tendon collagen content, and weekly animal activity scores. Results The ultimate load of PGE2-4 wks tendons at 4 weeks was significantly greater than control or saline group tendons. The stiffness and elastic modulus of the PGE2 injected tendons at 8 weeks was significantly greater than the control or saline tendons. No differences in animal activity, collagen content, or mean fibril diameter were observed between groups. Conclusions Four weekly peritendinous injections of PGE2 to the rat patellar

  12. Are Sport-Specific Profiles of Tendon Stiffness and Cross-Sectional Area Determined by Structural or Functional Integrity?

    Directory of Open Access Journals (Sweden)

    Hans-Peter Wiesinger

    Full Text Available The present study aimed to determine whether distinct sets of tendon properties are seen in athletes engaged in sports with contrasting requirements for tendon function and structural integrity. Patellar and Achilles tendon morphology and force-deformation relation were measured by combining ultrasonography, electromyography and dynamometry in elite ski jumpers, distance runners, water polo players and sedentary individuals. Tendon cross-sectional area normalized to body mass2/3 was smaller in water polo players than in other athletes (patellar and Achilles tendon; -28 to -24% or controls (patellar tendon only; -9%. In contrast, the normalized cross-sectional area was larger in runners (patellar tendon only; +26% and ski jumpers (patellar and Achilles tendon; +21% and +13%, respectively than in controls. Tendon stiffness normalized to body mass2/3 only differed in ski jumpers, compared to controls (patellar and Achilles tendon; +11% and +27%, respectively and to water polo players (Achilles tendon only; +23%. Tendon size appears as an adjusting variable to changes in loading volume and/or intensity, possibly to preserve ultimate strength or fatigue resistance. However, uncoupled morphological and mechanical properties indicate that functional requirements may also influence tendon adaptations.

  13. Structure and component alteration of rabbit Achilles tendon in tissue culture.

    Science.gov (United States)

    Hosaka, Yoshinao; Ueda, Hiromi; Yamasaki, Tadatsugu; Suzuki, Daisuke; Matsuda, Naoya; Takehana, Kazushige

    2005-12-01

    The aim of this study was to investigate alterations of cultured tendon tissues to determine whether tissue culture is a useful method for biological analyses of the tendon. Tendon tissues for tissue culture were isolated from Achilles tendons of rabbits. The tendon segments were placed one segment per well and incubated in growth medium consisting of Dullbecco's modified Eagle's medium supplemented with 5% fetal bovine serum at 37 degrees C in a humidified atmosphere with 5% CO(2) for various periods. The alignment of collagen fibrils was preserved for 48 h, but tendon structure has disintegrated at 96 h. Alcian blue staining and gelatine zymography revealed that proteoglycan markedly diminished and that matrix metalloproteinase (MMPs) activity was upregulated sharply at 72 and 96 h. The ratio of collagen fibrils with large diameter had increased and the mean diameter and mass average diameter value had reached maximum at 48 h. The values then decreased and mean diameters at 72 and 96 h were significantly different from that at 48 h. At 96 h, the ratio of collagen fibrils with small diameters had increased and collagen fibrils with large diameters had disappeared. These findings indicate that structural alteration is possible to be induced by disintegration of collagen fibrils and disappearance of glycosaminoglycans from extracellular matrix (ECM), subsequent of upregulation of MMPs activity. Although the study period is limited, the tissue culture method is available for investigating cell-ECM interaction in tendons.

  14. Coordinated development of muscles and tendon-like structures: early interactions in the Drosophila leg

    Directory of Open Access Journals (Sweden)

    cedric esoler

    2016-02-01

    Full Text Available The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates during the early steps of leg development, we affect the spatial localisation of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes.

  15. Is passive stiffness in human muscles related to the elasticity of tendon structures?

    Science.gov (United States)

    Kubo, K; Kanehisa, H; Fukunaga, T

    2001-08-01

    The purpose of this study was to examine in vivo whether passive stiffness in human muscles was related to the elasticity of tendon structures and to performance during stretch-shortening cycle exercise. Passive torque of plantar flexor muscles was measured during passive stretch from 90 degrees (anatomical position) to 65 degrees of dorsiflexion at a constant velocity of 5 degrees.s-1. The slope of the linear portion of the passive torque-angle curve during stretching was defined as the passive stiffness of the muscle. The elongation of the tendon and aponeurosis of the medial gastrocnemius muscle (MG) was directly measured using ultrasonography during ramp isometric plantar flexion up to the voluntary maximum. The relationship between the estimated muscle force of MG and tendon elongation was fitted to a linear regression, the slope of which was defined as the stiffness of the tendon. In addition, the dynamic torques during maximal voluntary concentric plantar flexion with and without prior eccentric contraction were determined at a constant velocity of 120 degrees.s-1. There were no significant correlations between passive stiffness and either the tendon stiffness (r = 0.19, P > 0.05) or the relative increase in torque with prior eccentric contraction (r = -0.19, P > 0.05). However, tendon stiffness was negatively correlated to the relative increase in torque output (r = -0.42, P tendon structures, and had no favourable effect on the muscle performance during stretch-shortening cycle exercise.

  16. Biomechanical and structural parameters of tendons in rats subjected to swimming exercise.

    Science.gov (United States)

    Bezerra, M A; Santos de Lira, K D; Coutinho, M P G; de Mesquita, G N; Novaes, K A; da Silva, R T B; de Brito Nascimento, A K; Inácio Teixeira, M F H B; Moraes, S R A

    2013-12-01

    The aim of this study was to evaluate the effect of swimming exercise, without overloading, on the biomechanical parameters of the calcaneal tendon of rats. 27 male Wistar rats (70 days) were distributed randomly into 2 groups, Control Group (CG; n=15) with restricted movements inside the cage and Swimming Group (SG; n=12), subjected to exercise training in a tank with a water temperature of 30±1°C, for 1 h/day, 5 days/week for 8 weeks. All animals were kept in a reversed light/dark cycle of 12 h with access to food and water ad libitum. After that, they were anesthetized and had their calcaneus tendons collected from their left rear paws. The tendon was submitted to a mechanical test on a conventional test machine. From the stress vs. strain curve, the biomechanical data were analyzed. For the statistical analysis, the Student-T test was used (penergy of deformation/tendon cross sectional area (p=0.017) and elastic modulus of the tendon (p=0.013) showed positive outcomes in SG. There was no difference in the other parameters. The results indicate that the swimming exercise training, without overloading, was an important stimulus for improving the biomechanical parameters and structural properties of the calcaneal tendon. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Comparison of Clinical and Structural Outcomes by Subscapularis Tendon Status in Massive Rotator Cuff Tear.

    Science.gov (United States)

    Lee, Sung Hyun; Nam, Dae Jin; Kim, Se Jin; Kim, Jeong Woo

    2017-09-01

    The subscapularis tendon is essential in maintaining normal glenohumeral biomechanics. However, few studies have addressed the outcomes of tears extending to the subscapularis tendon in massive rotator cuff tears. To assess the clinical and structural outcomes of arthroscopic repair of massive rotator cuff tears involving the subscapularis. Cohort study; Level of evidence, 3. Between January 2010 and January 2014, 122 consecutive patients with massive rotator cuff tear underwent arthroscopic rotator cuff repair. Overall, 122 patients were enrolled (mean age, 66 years; mean follow-up period, 39.5 months). Patients were categorized into 3 groups based on subscapularis tendon status: intact subscapularis tendon (I group; n = 45), tear involving less than the superior one-third (P group; n = 35), and tear involving more than one-third of the subscapularis tendon (C group; n = 42). All rotator cuff tears were repaired; however, subscapularis tendon tears involving less than the superior one-third in P group were only debrided. Pain visual analog scale, Constant, and American Shoulder and Elbow Surgeons scores and passive range of motion were measured preoperatively and at the final follow-up. Rotator cuff integrity, global fatty degeneration index, and occupation ratio were determined via magnetic resonance imaging preoperatively and 6 months postoperatively. We identified 37 retears (31.1%) based on postoperative magnetic resonance imaging evaluation. Retear rate in patients in the C group (47.6%) was higher than that in the I group (22.9%) or P group (20.0%) ( P = .011). Retear subclassification based on the involved tendons showed that subsequent subscapularis tendon retears were noted in only the C group. The improvement in clinical scores after repair was statistically significant in all groups but not different among the groups. Between-group comparison showed significant differences in preoperative external rotation ( P = .021). However, no statistically

  18. Evidence of structurally continuous collagen fibrils in tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Herchenhan, Andreas; Starborg, Tobias

    2017-01-01

    favor continuity. This study initially set out to trace the full length of individual fibrils in adult human tendons, using serial block face-scanning electron microscopy. But even with this advanced technique the required length could not be covered. Instead a statistical approach was used on a large...... volume of fibrils in shorter image stacks. Only a single end was observed after tracking 67.5 mm of combined fibril lengths, in support of fibril continuity. To shed more light on this observation, the full length of a short tendon (mouse stapedius, 125 μm) was investigated and continuity of individual...... fibrils was confirmed. In light of these results, possible mechanisms that could reconcile the opposing findings on fibril continuity are discussed. STATEMENT OF SIGNIFICANCE: Connective tissues hold all parts of the body together and are mostly constructed from thin threads of the protein collagen...

  19. MR anatomy study of the elbow, with emphasis in ligaments and tendons structure - methodology

    International Nuclear Information System (INIS)

    Vilela, Sonia de Aguiar; Fernandes, Artur da Rocha Correa; Barbieri, Antonio; Turrini, Elisabete; Juliano, Yara

    1999-01-01

    Seventeen MR exams of the elbow joints of fifteen healthy volunteers were obtained on T1 spin-echo sequences in the transversal, coronal and sagital planes. Eight anatomic structures were selected and evaluated by three independent blind readers. The aim of this study was to establish the frequency of visibility as well to determine the best plane to characterize these anatomic structures and also to analyze the interobserver variability. The readers analyzed the exams using the same criteria: degree 0 (structure not visible); degree 1 (structure visible and partially delineated); degree 2 (structure well visible and well delineated). The structure visibility showed variability close related to the degree (1 or 2) chosen by the readers to define the structure visualization and mainly in the transverse plane. The coronal plane was showed to be the ideal to evaluate the collateral ligaments, the common extensor tendon and the com,mon flexor tendon, otherwise the sagital plane was useful to define triceps and braquial tendons. The biceps tendon and annular ligament were well defined in the transverse plane. The usefulness of this study is to establish the ideal planes to evaluate these anatomic structures, and develop faster protocols. (author)

  20. Experimental diabetes induces structural, inflammatory and vascular changes of Achilles tendons.

    Directory of Open Access Journals (Sweden)

    Rodrigo R de Oliveira

    Full Text Available This study aims to demonstrate how the state of chronic hyperglycemia from experimental Diabetes Mellitus can influence the homeostatic imbalance of tendons and, consequently, lead to the characteristics of tendinopathy. Twenty animals were randomly divided into two experimental groups: control group, consisting of healthy rats and diabetic group constituted by rats induced to Diabetes Mellitus I. After twenty-four days of the induction of Diabetes type I, the Achilles tendon were removed for morphological evaluation, cellularity, number and cross-sectional area of blood vessel, immunohistochemistry for Collagen type I, VEGF and NF-κB nuclear localization sequence (NLS and nitrate and nitrite level. The Achilles tendon thickness (µm/100g of diabetic animals was significantly increased and, similarly, an increase was observed in the density of fibrocytes and mast cells in the tendons of the diabetic group. The average number of blood vessels per field, in peritendinous tissue, was statistically higher in the diabetic group 3.39 (2.98 vessels/field when compared to the control group 0.89 (1.68 vessels/field p = 0.001 and in the intratendinous region, it was observed that blood vessels were extremely rare in the control group 0.035 (0.18 vessels/field and were often present in the tendons of the diabetic group 0.89 (0.99 vessels/field. The immunohistochemistry analysis identified higher density of type 1 collagen and increased expression of VEGF as well as increased immunostaining for NFκB p50 NLS in the nucleus in Achilles tendon of the diabetic group when compared to the control group. Higher levels of nitrite/nitrate were observed in the experimental group induced to diabetes. We conclude that experimental DM induces notable structural, inflammatory and vascular changes in the Achilles tendon which are compatible with the process of chronic tendinopathy.

  1. Effect of cyclic training model on terminal structure of rabbit Achilles tendon: an experimental study

    Directory of Open Access Journals (Sweden)

    Chang-lin HUANG

    2012-05-01

    Full Text Available Objective  To observe the effect of cyclic training on histomorphology of the terminal structure of rabbit Achilles tendon, and explore its preventive effect on training-based enthesiopathy. Methods  Seventy-two Japanese white rabbits were randomly assigned to four groups: control group, jumping group, running group and cyclic training group, 18 for each. Three rabbits of each group were sacrificed at the 2nd, 3rd, 4th, 6th, 8th and 10th week. The terminal insertion tissues of bilateral Achilles tendons were harvested from these rabbits for observing the pathomorphological changes under light microscope, and pathological scoring and statistical analysis were carried out. Results  Light microscopy showed that the tendon fibers and fibrocartilage in the Achilles tendon insertion region were severely damaged in the jumping group, and though the tendon fibers were damaged severely, the injury to the fibrocartilage was comparatively less serious in the running group. The injuries to the tendon fibers and fibrocartilage were milder in the cyclic training group than in the jumping group and running group. In the 2nd, 3rd, 4th, 6th and 8th week, the histopathology score of insertion of Achilles tendon was 1.17±0.12, 2.19±0.15, 3.23±0.20, 4.66±0.16, 4.71±0.18, 4.63±0.13 respectively in the jumping group, and 1.16±0.13, 1.15±0.14, 2.18±0.12, 2.99±0.15, 3.98±0.16, 4.01±0.12 respectively in the running group. Increase in pathological score appeared earlier in the jumping group than in the running group, and a significant increase began at the 3rd week. The difference in pathological score between the two groups originated mainly from the changes in the tidemark. In the 2nd, 3rd, 4th, 6th, 8th and 10th week, the pathological score of Achilles tendon insertion was 1.13±0.14, 1.16±0.17, 1.15±0.13, 2.18±0.13, 2.17±0.12, 2.92±0.11 respectively in the cyclic training group, and they showed no significant changes as compared with control

  2. Electromechanical impedance-based health diagnosis for tendon and anchorage zone in a nuclear containment structure

    Science.gov (United States)

    Min, Jiyoung; Shim, Hyojin; Yun, Chung-Bang

    2012-04-01

    For a nuclear containment structure, the structural health monitoring is essential because of its high potential risk and grave social impact. In particular, the tendon and anchorage zone are to be monitored because they are under high tensile or compressive stress. In this paper, a method to monitor the tendon force and the condition of the anchorage zone is presented by using the impedance-based health diagnosis system. First, numerical simulations were conducted for cases with various loose tensile forces on the tendon as well as damages on the bearing plate and concrete structure. Then, experimental studies were carried out on a scaled model of the anchorage system. The relationship between the loose tensile force and the impedance-based damage index was analyzed by a regression analysis. When a structure gets damaged, the damage index increases so that the status of damage can be identified. The results of the numerical and experimental studies indicate a big potential of the proposed impedance-based method for monitoring the tendon and anchorage system.

  3. No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy

    NARCIS (Netherlands)

    de Vos, R. J.; Weir, A.; Tol, J. L.; Verhaar, J. A. N.; Weinans, H.; van Schie, H. T. M.

    2011-01-01

    To assess whether a platelet-rich plasma (PRP) injection leads to an enhanced tendon structure and neovascularisation, measured with ultrasonographic techniques, in chronic midportion Achilles tendinopathy. Double-blind, randomised, placebo-controlled clinical trial. Sports medical department of The

  4. Ultrasound assessment for grading structural tendon changes in supraspinatus tendinopathy: an inter-rater reliability study

    DEFF Research Database (Denmark)

    Ingwersen, Kim Gordon; Hjarbæk, John; Eshøj, Henrik

    2016-01-01

    Aim To evaluate the inter-rater reliability of measuring structural changes in the tendon of patients, clinically diagnosed with supraspinatus tendinopathy (cases) and healthy participants (controls), on ultrasound (US) images captured by standardised procedures. Methods A total of 40 participant...

  5. The influence of physical activity during youth on structural and functional properties of the Achilles tendon

    DEFF Research Database (Denmark)

    Lenskjold, A; Kongsgaard, M; Larsen, J O

    2015-01-01

    were either physically active (HAY) or inactive (LAY) in young age. Twelve men in HAY group and eight men in LAY group participated. Structural, functional, and biochemical properties of Achilles tendon were estimated from magnetic resonance imaging, ultrasound video recordings, mechanical tests...

  6. Composition and structure of porcine digital flexor tendon-bone insertion tissues.

    Science.gov (United States)

    Chandrasekaran, Sandhya; Pankow, Mark; Peters, Kara; Huang, Hsiao-Ying Shadow

    2017-11-01

    Tendon-bone insertion is a functionally graded tissue, transitioning from 200 MPa tensile modulus at the tendon end to 20 GPa tensile modulus at the bone, across just a few hundred micrometers. In this study, we examine the porcine digital flexor tendon insertion tissue to provide a quantitative description of its collagen orientation and mineral concentration by using Fast Fourier Transform (FFT) based image analysis and mass spectrometry, respectively. Histological results revealed uniformity in global collagen orientation at all depths, indicative of mechanical anisotropy, although at mid-depth, the highest fiber density, least amount of dispersion, and least cellular circularity were evident. Collagen orientation distribution obtained through 2D FFT of histological imaging data from fluorescent microscopy agreed with past measurements based on polarized light microscopy. Results revealed global fiber orientation across the tendon-bone insertion to be preserved along direction of physiologic tension. Gradation in the fiber distribution orientation index across the insertion was reflective of a decrease in anisotropy from the tendon to the bone. We provided elemental maps across the fibrocartilage for its organic and inorganic constituents through time-of-flight secondary ion mass spectrometry (TOF-SIMS). The apatite intensity distribution from the tendon to bone was shown to follow a linear trend, supporting past results based on Raman microprobe analysis. The merit of this study lies in the image-based simplified approach to fiber distribution quantification and in the high spatial resolution of the compositional analysis. In conjunction with the mechanical properties of the insertion tissue, fiber, and mineral distribution results for the insertion from this may potentially be incorporated into the development of a structural constitutive approach toward computational modeling. Characterizing the properties of the native insertion tissue would provide the

  7. Achilles tendon structure improves on UTC imaging over a 5-month pre-season in elite Australian football players.

    Science.gov (United States)

    Docking, S I; Rosengarten, S D; Cook, J

    2016-05-01

    Pre-season injuries are common and may be due to a reintroduction of training loads. Tendons are sensitive to changes in load, making them vulnerable to injury in the pre-season. This study investigated changes in Achilles tendon structure on ultrasound tissue characterization (UTC) over the course of a 5-month pre-season in elite male Australian football players. Eighteen elite male Australian football players with no history of Achilles tendinopathy and normal Achilles tendons were recruited. The left Achilles tendon was scanned with UTC to quantify the stability of the echopattern. Participants were scanned at the start and completion of a 5-month pre-season. Fifteen players remained asymptomatic over the course of the pre-season. All four echo-types were significantly different at the end of the pre-season, with the overall echopattern suggesting an improvement in Achilles tendon structure. Three of the 18 participants developed Achilles tendon pain that coincided with a change in the UTC echopattern. This study demonstrates that the UTC echopattern of the Achilles tendon improves over a 5-month pre-season training period, representing increased fibrillar alignment. However, further investigation is needed to elucidate with this alteration in the UTC echopattern results in improved tendon resilience and load capacity. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Changes in skeletal muscle and tendon structure and function following genetic inactivation of myostatin in rats

    Science.gov (United States)

    Mendias, Christopher L; Lynch, Evan B; Gumucio, Jonathan P; Flood, Michael D; Rittman, Danielle S; Van Pelt, Douglas W; Roche, Stuart M; Davis, Carol S

    2015-01-01

    Myostatin is a negative regulator of skeletal muscle and tendon mass. Myostatin deficiency has been well studied in mice, but limited data are available on how myostatin regulates the structure and function of muscles and tendons of larger animals. We hypothesized that, in comparison to wild-type (MSTN+/+) rats, rats in which zinc finger nucleases were used to genetically inactivate myostatin (MSTNΔ/Δ) would exhibit an increase in muscle mass and total force production, a reduction in specific force, an accumulation of type II fibres and a decrease and stiffening of connective tissue. Overall, the muscle and tendon phenotype of myostatin-deficient rats was markedly different from that of myostatin-deficient mice, which have impaired contractility and pathological changes to fibres and their extracellular matrix. Extensor digitorum longus and soleus muscles of MSTNΔ/Δ rats demonstrated 20–33% increases in mass, 35–45% increases in fibre number, 20–57% increases in isometric force and no differences in specific force. The insulin-like growth factor-1 pathway was activated to a greater extent in MSTNΔ/Δ muscles, but no substantial differences in atrophy-related genes were observed. Tendons of MSTNΔ/Δ rats had a 20% reduction in peak strain, with no differences in mass, peak stress or stiffness. The general morphology and gene expression patterns were similar between tendons of both genotypes. This large rodent model of myostatin deficiency did not have the negative consequences to muscle fibres and extracellular matrix observed in mouse models, and suggests that the greatest impact of myostatin in the regulation of muscle mass may not be to induce atrophy directly, but rather to block hypertrophy signalling. PMID:25640143

  9. Leg tendon glands in male bumblebees ( Bombus terrestris): structure, secretion chemistry, and possible functions

    Science.gov (United States)

    Jarau, Stefan; Žáček, Petr; Šobotník, Jan; Vrkoslav, Vladimír; Hadravová, Romana; Coppée, Audrey; Vašíčková, Soňa; Jiroš, Pavel; Valterová, Irena

    2012-12-01

    Among the large number of exocrine glands described in bees, the tarsal glands were thought to be the source of footprint scent marks. However, recent studies showed that the compounds used for marking by stingless bees are secreted by leg tendon instead of tarsal glands. Here, we report on the structure of leg tendon glands in males of Bombus terrestris, together with a description of the chemical composition of their secretions and respective changes of both during the males' lives. The ultrastructure of leg tendon glands shows that the secretory cells are located in three independent regions, separated from each other by unmodified epidermal cells: in the femur, tibia, and basitarsus. Due to the common site of secretion release, the organ is considered a single secretory gland. The secretion of the leg tendon glands of B. terrestris males differs in its composition from those of workers and queens, in particular by (1) having larger proportions of compounds with longer chain lengths, which we identified as wax esters; and (2) by the lack of certain hydrocarbons (especially long chain dienes). Other differences consist in the distribution of double bond positions in the unsaturated hydrocarbons that are predominantly located at position 9 in males but distributed at seven to nine different positions in the female castes. Double bond positions may change chemical and physical properties of a molecule, which can be recognized by the insects and, thus, may serve to convey specific information. The function of male-specific compounds identified from their tendon glands remains elusive, but several possibilities are discussed.

  10. Clinical improvements are not explained by changes in tendon structure on UTC following an exercise program for patellar tendinopathy.

    Science.gov (United States)

    van Ark, Mathijs; Rio, Ebonie; Cook, Jill; van den Akker-Scheek, Inge; Gaida, James E; Zwerver, Johannes; Docking, Sean

    2018-04-11

    The aim of this study was to investigate the effects of a 4-week in-season exercise program of isometric or isotonic exercises on tendon structure and dimensions as quantified by Ultrasound Tissue Characterization (UTC). Randomized clinical trial. Volleyball and basketball players (16-31 years, n=29) with clinically diagnosed patellar tendinopathy were randomized to a 4-week isometric or isotonic exercise program. The programs were designed to decrease patellar tendon pain. A baseline and 4-week UTC scan was used to evaluate change in tendon structure. No significant change in tendon structure or dimensions on UTC was detected after the exercise program, despite patellar tendinopathy symptoms improving. The percentage and mean cross-sectional area (mCSA) of aligned fibrillar structure (echo-types I+II) (Z=-0.414,p=0.679) as well as disorganized structure (echo-types III + IV) (Z=-0.370,p=0.711) did not change over the 4-week exercise program. Change in tendon structure and dimensions on UTC did not differ significantly between the groups. Structural properties and dimensions of the patellar tendon on UTC did not change after a 4-week isometric or isotonic exercise program for athletes with patellar tendinopathy in-season, despite an improvement of symptoms. It seems that structural improvements are not required for a positive clinical outcome.

  11. Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats

    Science.gov (United States)

    Cury, Diego Pulzatto; Dias, Fernando José; Miglino, Maria Angélica; Watanabe, Ii-sei

    2016-01-01

    Tendons are transition tissues that transfer the contractile forces generated by the muscles to the bones, allowing movement. The region where the tendon attaches to the bone is called bone-tendon junction or enthesis and may be classified as fibrous or fibrocartilaginous. This study aims to analyze the collagen fibers and the cells present in the bone-tendon junction using light microscopy and ultrastructural techniques as scanning electron microscopy and transmission electron microscopy. Forty male Wistar rats were used in the experiment, being 20 adult rats at 4 months-old and 20 elderly rats at 20 months-old. The hind limbs of the rats were removed, dissected and prepared to light microscopy, transmission electron microscopy and scanning electron microscopy. The aging process showed changes in the collagen fibrils, with a predominance of type III fibers in the elderly group, in addition to a decrease in the amount of the fibrocartilage cells, fewer and shorter cytoplasmic processes and a decreased synthetic capacity due to degradation of the organelles involved in synthesis. PMID:27078690

  12. Structural and Ultrastructural Characteristics of Bone-Tendon Junction of the Calcaneal Tendon of Adult and Elderly Wistar Rats.

    Directory of Open Access Journals (Sweden)

    Diego Pulzatto Cury

    Full Text Available Tendons are transition tissues that transfer the contractile forces generated by the muscles to the bones, allowing movement. The region where the tendon attaches to the bone is called bone-tendon junction or enthesis and may be classified as fibrous or fibrocartilaginous. This study aims to analyze the collagen fibers and the cells present in the bone-tendon junction using light microscopy and ultrastructural techniques as scanning electron microscopy and transmission electron microscopy. Forty male Wistar rats were used in the experiment, being 20 adult rats at 4 months-old and 20 elderly rats at 20 months-old. The hind limbs of the rats were removed, dissected and prepared to light microscopy, transmission electron microscopy and scanning electron microscopy. The aging process showed changes in the collagen fibrils, with a predominance of type III fibers in the elderly group, in addition to a decrease in the amount of the fibrocartilage cells, fewer and shorter cytoplasmic processes and a decreased synthetic capacity due to degradation of the organelles involved in synthesis.

  13. FIBRILLINS IN TENDON

    Directory of Open Access Journals (Sweden)

    Betti Giusti

    2016-10-01

    Full Text Available Tendons among connective tissue, mainly collagen, contain also elastic fibres made of fibrillin 1, fibrillin 2 and elastin that are broadly distributed in tendons and represent 1-2% of the dried mass of the tendon. Only in the last years, studies on structure and function of elastic fibres in tendons have been performed. Aim of this review is to revise data on the organization of elastic fibres in tendons, in particular fibrillin structure and function, and on the clinical manifestations associated to alterations of elastic fibres in tendons. Indeed, microfibrils may contribute to tendon mechanics; therefore, their alterations may cause joint hypermobility and contractures which have been found to be clinical features in patients with Marfan syndrome and Beals syndrome. The two diseases are caused by mutations in genes FBN1 and FBN2 encoding fibrillin 1 and fibrillin 2, respectively.

  14. Effect of acute resistance exercise and sex on human patellar tendon structural and regulatory mRNA expression

    DEFF Research Database (Denmark)

    Sullivan, B.E.; Carroll, C.C.; Jemiolo, B.

    2009-01-01

    Sullivan BE, Carroll CC, Jemiolo B, Trappe SW, Magnusson SP, Dossing S, Kjaer M, Trappe TA. Effect of acute resistance exercise and sex on human patellar tendon structural and regulatory mRNA expression. J Appl Physiol 106: 468-475, 2009. First published November 20, 2008; doi: 10.1152/japplphysiol.......91341.2008.-Tendon is mainly composed of collagen and an aqueous matrix of proteoglycans that are regulated by enzymes called matrix metalloproteinases ( MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Although it is known that resistance exercise (RE) and sex influence tendon metabolism...... and mechanical properties, it is uncertain what structural and regulatory components contribute to these responses. We measured the mRNA expression of tendon's main fibrillar collagens (type I and type III) and the main proteoglycans (decorin, biglycan, fibromodulin, and versican) and the regulatory enzymes MMP...

  15. Achilles tendons from decorin- and biglycan-null mouse models have inferior mechanical and structural properties predicted by an image-based empirical damage model.

    Science.gov (United States)

    Gordon, J A; Freedman, B R; Zuskov, A; Iozzo, R V; Birk, D E; Soslowsky, L J

    2015-07-16

    Achilles tendons are a common source of pain and injury, and their pathology may originate from aberrant structure function relationships. Small leucine rich proteoglycans (SLRPs) influence mechanical and structural properties in a tendon-specific manner. However, their roles in the Achilles tendon have not been defined. The objective of this study was to evaluate the mechanical and structural differences observed in mouse Achilles tendons lacking class I SLRPs; either decorin or biglycan. In addition, empirical modeling techniques based on mechanical and image-based measures were employed. Achilles tendons from decorin-null (Dcn(-/-)) and biglycan-null (Bgn(-/-)) C57BL/6 female mice (N=102) were used. Each tendon underwent a dynamic mechanical testing protocol including simultaneous polarized light image capture to evaluate both structural and mechanical properties of each Achilles tendon. An empirical damage model was adapted for application to genetic variation and for use with image based structural properties to predict tendon dynamic mechanical properties. We found that Achilles tendons lacking decorin and biglycan had inferior mechanical and structural properties that were age dependent; and that simple empirical models, based on previously described damage models, were predictive of Achilles tendon dynamic modulus in both decorin- and biglycan-null mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Structural and mechanical multi-scale characterization of white New-Zealand rabbit Achilles tendon.

    Science.gov (United States)

    Kahn, Cyril J F; Dumas, Dominique; Arab-Tehrany, Elmira; Marie, Vanessa; Tran, Nguyen; Wang, Xiong; Cleymand, Franck

    2013-10-01

    Multi-scale characterization of structures and mechanical behavior of biological tissues are of huge importance in order to evaluate the quality of a biological tissue and/or to provide bio-inspired scaffold for functional tissue engineering. Indeed, the more information on main biological tissue structures we get, the more relevant we will be to design new functional prostheses for regenerative medicine or to accurately evaluate tissues. From this perspective, we have investigated the structures and their mechanical properties from nanoscopic to macroscopic scale of fresh ex-vivo white New-Zealand rabbit Achilles tendon using second harmonic generation (SHG) microscopy, atomic force microscopy (AFM) and tensile tests to provide a "simple" model whose parameters are relevant of its micro or nano structure. Thus, collagen fiber's crimping was identified then measured from SHG images as a plane sine wave with 28.4 ± 5.8 μm of amplitude and 141 ± 41 μm of wavelength. Young's moduli of fibrils (3.0 GPa) and amorphous phases (223 MPa) were obtained using TH-AFM. From these investigations, a non-linear Zener model linking a statistical Weibull's distribution of taut fibers under traction to crimp fibers were developed. This model showed that for small strain (tendon observations under static or dynamic solicitations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Effect of cyclic training model on terminal structure of rabbit Achilles tendon: an experimental study

    OpenAIRE

    Chang-lin HUANG; Wang GAO; Tao HUANG; Zhen-hai GUO

    2012-01-01

    Objective  To observe the effect of cyclic training on histomorphology of the terminal structure of rabbit Achilles tendon, and explore its preventive effect on training-based enthesiopathy. Methods  Seventy-two Japanese white rabbits were randomly assigned to four groups: control group, jumping group, running group and cyclic training group, 18 for each. Three rabbits of each group were sacrificed at the 2nd, 3rd, 4th, 6th, 8th and 10th week. The terminal insertion tissues of bilateral Achil...

  18. The Tendon Structure Returns to Asymptomatic Values in Nonoperatively Treated Achilles Tendinopathy but Is Not Associated With Symptoms: A Prospective Study.

    Science.gov (United States)

    de Jonge, Suzan; Tol, Johannes L; Weir, Adam; Waarsing, Jan H; Verhaar, Jan A N; de Vos, Robert-Jan

    2015-12-01

    Tendinopathy is characterized by alterations in the tendon structure, but there are conflicting results on the potential of tendon structure normalization and no large studies on the quantified, ultrasonographic tendon structure and its association with symptoms. To determine whether the tendon structure returns to values of asymptomatic individuals after treatment with 2 substances injected within the tendon, to assess the association between the tendon structure and symptoms, and to assess the prognostic value of the baseline tendon structure on treatment response. Cohort study; Level of evidence, 2. This study was part of a randomized trial on chronic midportion Achilles tendinopathy using eccentric exercises with either a platelet-rich plasma or saline injection. Symptoms were recorded using the Victorian Institute of Sports Assessment-Achilles (VISA-A) questionnaire. The tendon structure was quantified with ultrasound tissue characterization (UTC); echo types I + II (as a percentage of total tendon types I-IV) are structure related. Follow-up was at 6, 12, 24, and 52 weeks. A control group of asymptomatic subjects (similar age) was selected to compare the tendon structure. Patient symptoms were correlated with the tendon structure using a linear model. Fifty-four patients were included in the symptomatic group. The mean (± SD) echo types I + II in the symptomatic group increased significantly from 74.6% ± 10.8% at baseline to 85.6% ± 6.0% at 24-week follow-up. The result for echo types I + II at 24 weeks was not significantly different (P = .198) from that of the asymptomatic control group (87.5% ± 6.0%). In 54 repeated measurements at 5 time points, the adjusted percentage of echo types I + II was not associated with the VISA-A score (main effect: β = .12; 95% CI, -0.12 to 0.35; P = .338). The adjusted baseline echo types I + II were not associated with a change in the VISA-A score from baseline to 52 weeks (β = -.15; 95% CI, -0.67 to 0.36; P = .555

  19. Achilles tendon and sports

    International Nuclear Information System (INIS)

    Ulreich, N.; Kainberger, F.; Huber, W.; Nehrer, S.

    2002-01-01

    Because of the rising popularity of recreational sports activities achillodynia is an often associated symptom with running, soccer and athletics. Therefore radiologist are frequently asked to image this tendon. The origin of the damage of the Achilles tendon is explained by numerous hypothesis, mainly a decreased perfusion and a mechanical irritation that lead to degeneration of the tendon. High-resolution technics such as sonography and magnetic resonance imaging show alterations in the structure of the tendon which can be graduated and classified. Manifestations like tendinosis, achillobursitis, rupture and Haglunds disease can summarized as the tendon overuse syndrom. A rupture of a tendon is mostly the result of a degeneration of the collagenfibres. The task of the radiologist is to acquire the intrinsic factors for a potential rupture. (orig.) [de

  20. Tendon surveillance requirements - average tendon force

    International Nuclear Information System (INIS)

    Fulton, J.F.

    1982-01-01

    Proposed Rev. 3 to USNRC Reg. Guide 1.35 discusses the need for comparing, for individual tendons, the measured and predicted lift-off forces. Such a comparison is intended to detect any abnormal tendon force loss which might occur. Recognizing that there are uncertainties in the prediction of tendon losses, proposed Guide 1.35.1 has allowed specific tolerances on the fundamental losses. Thus, the lift-off force acceptance criteria for individual tendons appearing in Reg. Guide 1.35, Proposed Rev. 3, is stated relative to a lower bound predicted tendon force, which is obtained using the 'plus' tolerances on the fundamental losses. There is an additional acceptance criterion for the lift-off forces which is not specifically addressed in these two Reg. Guides; however, it is included in a proposed Subsection IWX to ASME Code Section XI. This criterion is based on the overriding requirement that the magnitude of prestress in the containment structure be sufficeint to meet the minimum prestress design requirements. This design requirement can be expressed as an average tendon force for each group of vertical hoop, or dome tendons. For the purpose of comparing the actual tendon forces with the required average tendon force, the lift-off forces measured for a sample of tendons within each group can be averaged to construct the average force for the entire group. However, the individual lift-off forces must be 'corrected' (normalized) prior to obtaining the sample average. This paper derives the correction factor to be used for this purpose. (orig./RW)

  1. Implications of obesity for tendon structure, ultrastructure and biochemistry: a study on Zucker rats.

    Science.gov (United States)

    Biancalana, Adriano; Velloso, Lício Augusto; Taboga, Sebastião Roberto; Gomes, Laurecir

    2012-02-01

    The extracellular matrix consists of collagen, proteoglycans and non-collagen proteins. The incidence of obesity and associated diseases is currently increasing in developed countries. Obesity is considered to be a disease of modern times, and genes predisposing to the disease have been identified in humans and animals. The objective of the present study was to compare the morphological and biochemical aspects of the deep digital flexor tendon of lean (Fa/Fa or Fa/fa) and genetically obese (fa/fa) Zucker rats. Ultrastructural analysis showed the presence of lipid droplets in both groups, whereas disorganized collagen fibril bundles were observed in obese animals. Lean animals presented a larger amount of non-collagen proteins and glycosaminoglycans than obese rats. We propose that the overweight and lesser physical activity in obese animals may have provoked the alterations in the composition and organization of extracellular matrix components but a genetic mechanism cannot be excluded. These alterations might be related to organizational and structural modifications in the collagen bundles that influence the mechanical properties of tendons and the progression to a pathological state. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Achilles Tendonitis

    Science.gov (United States)

    ... almost impossible. Achilles tendonitis is a very common running injury. But it can also affect basketball players, dancers, ... Proximal Biceps Tendonitis Safety Tips: Basketball Safety Tips: Running Repetitive Stress Injuries Sports and Exercise Safety Dealing With Sports Injuries ...

  3. Structural and functional assessment of intense therapeutic ultrasound effects on partial Achilles tendon transection

    Science.gov (United States)

    Barton, Jennifer K.; Rice, Photini S.; Howard, Caitlin C.; Koevary, Jen W.; Danford, Forest; Gonzales, David A.; Vande Geest, Jon; Latt, L. Daniel; Szivek, John A.; Amodei, Richard; Slayton, Michael

    2018-02-01

    Tendinopathies and tendon tears heal slowly because tendons have a limited blood supply. Intense therapeutic ultrasound (ITU) is a treatment modality that creates very small, focal coagula in tissue, which can stimulate a healing response. This pilot study investigated the effects of ITU on rabbit and rat models of partial Achilles tendon rupture. The right Achilles tendons of 20 New Zealand White rabbits and 118 rats were partially transected. Twenty-four hours after surgery, ITU coagula were placed in the tendon and surrounding tissue, alternating right and left legs. At various time points, the following data were collected: ultrasound imaging, optical coherence tomography (OCT) imaging, mechanical testing, gene expression analysis, histology, and multiphoton microscopy (MPM) of sectioned tissue. Ultrasound visualized cuts and treatment lesions. OCT showed the effect of the interventions on birefringence banding caused by collagen organization. MPM showed inflammatory infiltrate, collagen synthesis and organization. By day 14- 28, all tendons had a smooth appearance and histology, MPM and OCT still could still visualize residual healing processes. Few significant results in gene expression were seen, but trends were that ITU treatment caused an initial decrease in growth and collagen gene expression followed by an increase. No difference in failure loads was found between control, cut, and ITU treatment groups, suggesting that sufficient healing had occurred by 14 days to restore all test tissue to control mechanical properties. These results suggest that ITU does not cause harm to tendon tissue. Upregulation of some genes suggests that ITU may increase healing response.

  4. Analysis of initial prestress force of spatial tendon prestressed concrete containment structures

    International Nuclear Information System (INIS)

    Shiau, H.-S.

    1975-01-01

    A theoretical investigation is presented of the initial stage of prestressed tendon and prestressed concrete before and after jacking force of tendon anchorage released. A method is developed that is applicable to any kind of spatial tendon considering frictional loss due to length and curvature effects. A triple integral equation of one independent variable and jacking force is derived to represent an exact solution of tendon force along the whole tendon which may have reverse curvatures. In order to analyze the stress response of concrete due to this prestress force by using existing finite element computer program or any other kind of computer program, a systematic method is suggested to obtain tendon force components, which are represented by a series of equations of one independent variable, in any coordinate system as external force applied on the concrete. The resulting systems of the equations are then solved by numerical mathematic and computer techniques. Two numerical examples are represented. The first example is, dome prestress analysis of containment building by the proposed method and Kalnins' computer program for shell of revolution. Results are discussed. The second example is picked from prestress analysis for personnel air lock of containment building by using proposed method and FELAP finite element Computer program. It includes two different tendon arrangements around the opening. The results of these two different arrangements are compared and discussed

  5. Analysis of in-service inspection guides for post-tensioning systems in containment structures with greased tendons

    International Nuclear Information System (INIS)

    Bae, I. H.; Choi, I. G.; Seo, J. M.

    2000-01-01

    Prestressed concrete containments(PCC) are inspected periodically to ensure structural integrity and to identify and correct problems before they come critical. These inspections are conducted in accordance with the Nuclear Regulatory Committee(NRC) Regulatory Guide. As experience with the surveillance mounts, the guide is revised to keep pace with technological advances in containment design and to reflect the knowledge obtained experience. In the study, an analysis of the available utility surveillance data and an evaluation of the NRC Regulatory Guide and the ASME Code are conducted. The results indicate that the average value of the lower bound defined in Regulatory Guide 1.35.1 can be less than the minimum required force level at 40 years for the existing containment and thus an acceptable alternative has to be presented to meet the allowance of the guide. Tendons in excess of the upper bound or 70% of the ultimate tensile strength of the tendon are observed. Such an occurrence indicates tendon behavior outside the tolerance band that expected, and the cause of such behavior has to be investigated. It is shown that the behavior of the predicted prestressing force with time based on assumed losses does quite different from that of the measured tendon force with time and, therefore, studies for the significant factors, such as shrinkage and creep of concrete, that influence the time-dependent losses in PCC are needed. Additional research on the long-term effects of the impurity levels on the effectiveness of the grease seems justified

  6. [Posterior tibial tendon dysfunction: what other structures are involved in the development of acquired adult flat foot?].

    Science.gov (United States)

    Herráiz Hidalgo, L; Carrascoso Arranz, J; Recio Rodríguez, M; Jiménez de la Peña, M; Cano Alonso, R; Álvarez Moreno, E; Martínez de Vega Fernández, V

    2014-01-01

    To evaluate the association of posterior tibial tendon dysfunction and lesions of diverse ankle structures diagnosed at MRI with radiologic signs of flat foot. We retrospectively compared 29 patients that had posterior tibial tendon dysfunction (all 29 studied with MRI and 21 also studied with weight-bearing plain-film X-rays) with a control group of 28 patients randomly selected from among all patients who underwent MRI and weight-bearing plain-film X-rays for other ankle problems. In the MRI studies, we analyzed whether a calcaneal spur, talar beak, plantar fasciitis, calcaneal bone edema, Achilles' tendinopathy, spring ligament injury, tarsal sinus disease, and tarsal coalition were present. In the weight-bearing plain-film X-rays, we analyzed the angle of Costa-Bertani and radiologic signs of flat foot. To analyze the differences between groups, we used Fisher's exact test for the MRI findings and for the presence of flat foot and analysis of variance for the angle of Costa-Bertani. Calcaneal spurs, talar beaks, tarsal sinus disease, and spring ligament injury were significantly more common in the group with posterior tibial tendon dysfunction (P<.05). Radiologic signs of flat foot and anomalous values for the angle of Costa-Bertani were also significantly more common in the group with posterior tibial tendon dysfunction (P<.001). We corroborate the association between posterior tibial tendon dysfunction and lesions to the structures analyzed and radiologic signs of flat foot. Knowledge of this association can be useful in reaching an accurate diagnosis. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

  7. DOES AEROBIC EXERCISE TRAINING PROMOTE CHANGES IN STRUCTURAL AND BIOMECHANICAL PROPERTIES OF THE TENDONS IN EXPERIMENTAL ANIMALS? A SYSTEMATIC REVIEW

    Directory of Open Access Journals (Sweden)

    Márcio A. Bezerra

    2012-11-01

    Full Text Available To develop a systematic review to evaluate, through the best scientific evidence available, the effectiveness of aerobic exercise in improving the biomechanical characteristics of tendons in experimental animals. Two independent assessors conducted a systematic search in the databases Medline/PUBMED and Lilacs/BIREME, using the following descriptors of Mesh in animal models. The ultimate load of traction and the elastic modulus tendon were used as primary outcomes and transverse section area, ultimate stress and tendon strain as secondary outcomes. The assessment of risk of bias in the studies was carried out using the following methodological components: light/dark cycle, temperature, nutrition, housing, research undertaken in conjunction with an ethics committee, randomization, adaptation of the animals to the training and preparation for the mechanical test. Eight studies, comprising 384 animals, were selected; it was not possible to combine them into one meta-analysis due to the heterogeneity of the samples. There was a trend to increasing ultimate load without changes in the other outcomes studied. Only one study met more than 80% of the quality criteria. Physical training performed in a structured way with imposition of overloads seems to be able to promote changes in tendon structure of experimental models by increasing the ultimate load supported. However, the results of the influence of exercise on the elastic modulus parameters, strain, transverse section area and ultimate stress, remain controversial and inconclusive. Such a conclusion must be evaluated with reservation as there was low methodological control in the studies included in this review.

  8. Chronic alterations in growth hormone/insulin-like growth factor-I signaling lead to changes in mouse tendon structure

    DEFF Research Database (Denmark)

    Nielsen, R H; Clausen, N M; Schjerling, P

    2014-01-01

    transgenic mice that expressed bovine GH (bGH) and had high circulating levels of GH and IGF-I, 2) dwarf mice with a disrupted GH receptor gene (GHR-/-) leading to GH resistance and low circulating IGF-I, and 3) a wild-type control group (CTRL). We measured the ultra-structure, collagen content and m......The growth hormone/insulin-like growth factor-I (GH/IGF-I) axis is an important stimulator of collagen synthesis in connective tissue, but the effect of chronically altered GH/IGF-I levels on connective tissue of the muscle-tendon unit is not known. We studied three groups of mice; 1) giant......-/- mice had significantly lower collagen fibril volume fraction in Achilles tendon, as well as decreased mRNA expression of IGF-I isoforms and collagen types I and III in muscle compared to CTRL. In contrast, the mRNA expression of IGF-I isoforms and collagens in bGH mice was generally high in both tendon...

  9. Novel methods for tendon investigations

    DEFF Research Database (Denmark)

    Kjær, Michael; Langberg, Henning; Bojsen-Møller, J.

    2008-01-01

    Purpose. Tendon structures have been studied for decades, but over the last decade, methodological development and renewed interest for metabolic, circulatory and tissue protein turnover in tendon tissue has resulted in a rising amount of investigations. Method. This paper will detail the various...... modern investigative techniques available to study tendons. Results. There are a variety of investigative methods available to study the correlations between mechanics and biology in tendons. Conclusion. The available methodologies not only allow for potential insight into physiological...... and pathophysiological mechanisms in tendon tissue, but also, to some extent, allow for more elaborate studies of the intact human tendon. Read More: http://informahealthcare.com/doi/full/10.1080/09638280701785403...

  10. From mechanical loading to collagen synthesis, structural changes and function in human tendon

    DEFF Research Database (Denmark)

    Kjaer, M; Langberg, H; Heinemeier, K

    2009-01-01

    The adaptive response of connective tissue to loading requires increased synthesis and turnover of matrix proteins, with special emphasis on collagen. Collagen formation and degradation in the tendon increases with both acute and chronic loading, and data suggest that a gender difference exists...

  11. Leg tendon glands in male bumblebees (Bombus terrestris): structure, secretion chemistry, and possible functions

    Czech Academy of Sciences Publication Activity Database

    Jarau, S.; Žáček, Petr; Šobotník, Jan; Vrkoslav, Vladimír; Hadravová, Romana; Coppée, Audrey; Vašíčková, Soňa; Jiroš, Pavel; Valterová, Irena

    2012-01-01

    Roč. 99, č. 12 (2012), s. 1039-1049 ISSN 0028-1042 R&D Projects: GA TA ČR TA01020969 Institutional support: RVO:61388963 Keywords : bumblebee * hydrocarbons * leg tendon glands * sex specific secretion * wax esters Subject RIV: CC - Organic Chemistry Impact factor: 2.144, year: 2012

  12. Collagen V haploinsufficiency in a murine model of classic Ehlers-Danlos syndrome is associated with deficient structural and mechanical healing in tendons.

    Science.gov (United States)

    Johnston, Jessica M; Connizzo, Brianne K; Shetye, Snehal S; Robinson, Kelsey A; Huegel, Julianne; Rodriguez, Ashley B; Sun, Mei; Adams, Sheila M; Birk, David E; Soslowsky, Louis J

    2017-12-01

    Classic Ehlers-Danlos syndrome (EDS) patients suffer from connective tissue hyperelasticity, joint instability, skin hyperextensibility, tissue fragility, and poor wound healing due to heterozygous mutations in COL5a1 or COL5a2 genes. This study investigated the roles of collagen V in establishing structure and function in uninjured patellar tendons as well as in the injury response using a Col5a1 +/- mouse, a model for classic EDS. These analyses were done comparing tendons from a classic EDS model (Col5a1 +/- ) with wild-type controls. Tendons were subjected to mechanical testing, histological, and fibril analysis before injury as well as 3 and 6 weeks after injury. We found that Col5a1 +/- tendons demonstrated diminished recovery of mechanical competency after injury as compared to normal wild-type tendons, which recovered their pre-injury values by 6 weeks post injury. Additionally, the Col5a1 +/- tendons demonstrated altered fibril morphology and diameter distributions compared to the wild-type tendons. This study indicates that collagen V plays an important role in regulating collagen fibrillogenesis and the associated recovery of mechanical integrity in tendons after injury. In addition, the dysregulation with decreased collagen V expression in EDS is associated with a diminished injury response. The results presented herein have the potential to direct future targeted therapeutics for classic EDS patients. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2707-2715, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  13. Diagnostic value of tendon thickness and structure in the sonographic diagnosis of supraspinatus tendinopathy: room for a two-step approach.

    Science.gov (United States)

    Arend, Carlos Frederico; Arend, Ana Amalia; da Silva, Tiago Rodrigues

    2014-06-01

    The aim of our study was to systematically compare different methodologies to establish an evidence-based approach based on tendon thickness and structure for sonographic diagnosis of supraspinatus tendinopathy when compared to MRI. US was obtained from 164 symptomatic patients with supraspinatus tendinopathy detected at MRI and 42 asymptomatic controls with normal MRI. Diagnostic yield was calculated for either maximal supraspinatus tendon thickness (MSTT) and tendon structure as isolated criteria and using different combinations of parallel and sequential testing at US. Chi-squared tests were performed to assess sensitivity, specificity, and accuracy of different diagnostic approaches. Mean MSTT was 6.68 mm in symptomatic patients and 5.61 mm in asymptomatic controls (P6.0mm provided best results for accuracy (93.7%) when compared to other measurements of tendon thickness. Also as an isolated criterion, abnormal tendon structure (ATS) yielded 93.2% accuracy for diagnosis. The best overall yield was obtained by both parallel and sequential testing using either MSTT>6.0mm or ATS as diagnostic criteria at no particular order, which provided 99.0% accuracy, 100% sensitivity, and 95.2% specificity. Among these parallel and sequential tests that provided best overall yield, additional analysis revealed that sequential testing first evaluating tendon structure required assessment of 258 criteria (vs. 261 for sequential testing first evaluating tendon thickness and 412 for parallel testing) and demanded a mean of 16.1s to assess diagnostic criteria and reach the diagnosis (vs. 43.3s for sequential testing first evaluating tendon thickness and 47.4s for parallel testing). We found that using either MSTT>6.0mm or ATS as diagnostic criteria for both parallel and sequential testing provides the best overall yield for sonographic diagnosis of supraspinatus tendinopathy when compared to MRI. Among these strategies, a two-step sequential approach first assessing tendon

  14. Fibrin Gels Exhibit Improved Biological, Structural, and Mechanical Properties Compared with Collagen Gels in Cell-Based Tendon Tissue-Engineered Constructs

    Science.gov (United States)

    Dyment, Nathaniel A.; Lu, Yinhui; Rao, Marepalli; Shearn, Jason T.; Rowe, David W.; Kadler, Karl E.; Butler, David L.

    2015-01-01

    The prevalence of tendon and ligament injuries and inadequacies of current treatments is driving the need for alternative strategies such as tissue engineering. Fibrin and collagen biopolymers have been popular materials for creating tissue-engineered constructs (TECs), as they exhibit advantages of biocompatibility and flexibility in construct design. Unfortunately, a few studies have directly compared these materials for tendon and ligament applications. Therefore, this study aims at determining how collagen versus fibrin hydrogels affect the biological, structural, and mechanical properties of TECs during formation in vitro. Our findings show that tendon and ligament progenitor cells seeded in fibrin constructs exhibit improved tenogenic gene expression patterns compared with their collagen-based counterparts for approximately 14 days in culture. Fibrin-based constructs also exhibit improved cell-derived collagen alignment, increased linear modulus (2.2-fold greater) compared with collagen-based constructs. Cyclic tensile loading, which promotes the maturation of tendon constructs in a previous work, exhibits a material-dependent effect in this study. Fibrin constructs show trending reductions in mechanical, biological, and structural properties, whereas collagen constructs only show improved tenogenic expression in the presence of mechanical stimulation. These findings highlight that components of the mechanical stimulus (e.g., strain amplitude or time of initiation) need to be tailored to the material and cell type. Given the improvements in tenogenic expression, extracellular matrix organization, and material properties during static culture, in vitro findings presented here suggest that fibrin-based constructs may be a more suitable alternative to collagen-based constructs for tissue-engineered tendon/ligament repair. PMID:25266738

  15. Microstructural stress relaxation mechanics in functionally different tendons.

    Science.gov (United States)

    Screen, H R C; Toorani, S; Shelton, J C

    2013-01-01

    Tendons experience widely varying loading conditions in vivo. They may be categorised by their function as either positional tendons, which are used for intricate movements and experience lower stress, or as energy storage tendons which act as highly stressed springs during locomotion. Structural and compositional differences between tendons are thought to enable an optimisation of their properties to suit their functional environment. However, little is known about structure-function relationships in tendon. This study adopts porcine flexor and extensor tendon fascicles as examples of high stress and low stress tendons, comparing their mechanical behaviour at the micro-level in order to understand their stress relaxation response. Stress-relaxation was shown to occur predominantly through sliding between collagen fibres. However, in the more highly stressed flexor tendon fascicles, more fibre reorganisation was evident when the tissue was exposed to low strains. By contrast, the low load extensor tendon fascicles appears to have less capacity for fibre reorganisation or shearing than the energy storage tendon, relying more heavily on fibril level relaxation. The extensor fascicles were also unable to sustain loads without rapid and complete stress relaxation. These findings highlight the need to optimise tendon repair solutions for specific tendons, and match tendon properties when using grafts in tendon repairs. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Mechanical Properties of Human Patellar Tendon at the Hierarchical levels of Tendon and Fibril

    DEFF Research Database (Denmark)

    Svensson, Rene Brüggebusch; Hansen, Philip; Hassenkam, Tue

    2012-01-01

    Tendons are strong hierarchical structures, but how tensile forces are transmitted between different levels remains incompletely understood. Collagen fibrils are thought to be primary determinants of whole tendon properties, and therefore we hypothesized that the whole human patellar tendon and its...... distinct collagen fibrils would display similar mechanical properties. Human patellar tendons (n=5) were mechanically tested in vivo by ultrasonography. Biopsies were obtained from each tendon and individual collagen fibrils were dissected and tested mechanically by atomic force microscopy. The Young...... that of tendon supports that fibrillar rather than interfibrillar properties govern sub-failure tendon response, making the fibrillar level a meaningful target of intervention. The lower modulus found in vitro suggests a possible adverse effect of removing the tissue from its natural environment. In addition...

  17. Tendon Force Transmission at the Nanoscale

    DEFF Research Database (Denmark)

    Svensson, René

    2013-01-01

    of connective tissue function that are poorly understood. One such aspect is the microscopic mechanisms of force transmission through tendons over macroscopic distances. Force transmission is at the heart of tendon function, but the large range of scales in the hierarchical structure of tendons has made...... it difficult to tackle. The tendon hierarchy ranges from molecules (2 nm) over fibrils (200 nm), fibers (2 μm) and fascicles (200 μm) to tendons (10 mm), and to derive the mechanisms of force transmission it is necessary to know the mechanical behavior at each hierarchical level. The aim of the present work...... was to elucidate the mechanisms of force transmission in tendons primarily by investigating the mechanical behavior at the hierarchical level of collagen fibrils. To do so we have developed an atomic force microscopy (AFM) method for tensile testing of native collagen fibrils. The thesis contains five papers...

  18. Iliopsoas Tendon Reformation after Psoas Tendon Release

    Directory of Open Access Journals (Sweden)

    K. Garala

    2013-01-01

    Full Text Available Internal snapping hip syndrome, or psoas tendonitis, is a recognised cause of nonarthritic hip pain. The majority of patients are treated conservatively; however, occasionally patients require surgical intervention. The two surgical options for iliopsoas tendinopathy are step lengthening of the iliopsoas tendon or releasing the tendon at the lesser trochanter. Although unusual, refractory snapping usually occurs soon after tenotomy. We report a case of a 47-year-old active female with internal snapping and pain following an open psoas tenotomy. Postoperatively she was symptom free for 13 years. An MRI arthrogram revealed reformation of a pseudo iliopsoas tendon reinserting into the lesser trochanter. The pain and snapping resolved after repeat iliopsoas tendon release. Reformation of tendons is an uncommon sequela of tenotomies. However the lack of long-term studies makes it difficult to calculate prevalence rates. Tendon reformation should be included in the differential diagnosis of failed tenotomy procedures after a period of symptom relief.

  19. Relationships Between Lower-Body Muscle Structure and Lower-Body Strength, Power, and Muscle-Tendon Complex Stiffness.

    Science.gov (United States)

    Secomb, Josh L; Lundgren, Lina E; Farley, Oliver R L; Tran, Tai T; Nimphius, Sophia; Sheppard, Jeremy M

    2015-08-01

    The purpose of this study was to determine whether any relationships were present between lower-body muscle structure and strength and power qualities. Fifteen elite male surfing athletes performed a battery of lower-body strength and power tests, including countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), and had their lower-body muscle structure assessed with ultrasonography. In addition, lower-body muscle-tendon complex (MTC) stiffness and dynamic strength deficit (DSD) ratio were calculated from the CMJ and IMTP. Significant relationships of large to very large strength were observed between the vastus lateralis (VL) thickness of the left (LVL) and right (RVL) leg and peak force (PF) (r = 0.54-0.77, p well as IMTP PF (r = 0.53-0.60, p = 0.02-0.04). Furthermore, large relationships were found between left lateral gastrocnemius (LG) pennation angle and SJ and IMTP PF (r = 0.53, p = 0.04, and r = 0.70, p < 0.01, respectively) and between LG and IMTP relative PF (r = 0.63, p = 0.01). Additionally, large relationships were identified between lower-body MTC stiffness and DSD ratio (r = 0.68, p < 0.01), right (LG) pennation angle (r = 0.51, p = 0.05), CMJ PF (r = 0.60, p = 0.02), and jump height (r = 0.53, p = 0.04). These results indicate that greater VL thickness and increased LG pennation angle are related to improved performance in the CMJ, SJ, and IMTP. Furthermore, these results suggest that lower-body MTC stiffness explains a large amount of variance in determining an athlete's ability to rapidly apply force during a dynamic movement.

  20. Calcaneal tendon: imaging findings

    International Nuclear Information System (INIS)

    Montandon, Cristiano; Fonseca, Cristiano Rezio; Montandon Junior, Marcelo Eustaquio; Lobo, Leonardo Valadares; Ribeiro, Flavia Aparecida de Souza; Teixeira, Kim-Ir-Sen Santos

    2003-01-01

    We reviewed the radiological and clinical features of 23 patients with calcaneal tendon diseases, who were submitted to ultrasound or magnetic resonance imaging. The objective of this study was to characterize the lesions for a precise diagnosis of calcaneal tendon injuries. A wide range of calcaneal tendon diseases include degenerative lesions, inflammation of the peritendinous tissue such as peritendinitis and bursitis, and rupture. Imaging methods are essential in the diagnosis, treatment and follow-up of calcaneal tendon diseases. (author)

  1. Tendon Transfer Surgery

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... DESCRIPTION The tendon is the strong cord at either end of a muscle that is attached to bone. Tendons , combined with ...

  2. THE ROLE OF DETRAINING IN TENDON MECHANOBIOLOGY

    Directory of Open Access Journals (Sweden)

    Antonio eFrizziero

    2016-02-01

    Full Text Available Introduction: Several conditions such as training, aging, estrogen deficiency and drugs could affect the biological and anatomo-physiological characteristics of the tendon. Additionally, recent preclinical and clinical studies examined the effect of detraining on tendon, showing alterations in its structure and morphology and in tenocyte mechanobiology. However, there is a paucity of data examining the impact that cessation of training may have on tendon. In practice, we do not fully understand how tendons respond to a period of training followed by sudden detraining. Therefore, within this review, we summarize the studies where tendon detraining was examined.Materials and methods: A descriptive systematic literature review was conducted by searching three databases (PubMed, Scopus and Web of Knowledge on tendon detraining. Original articles in English from 2000 to 2015 were included. In addition, the search was extended to the reference lists of the selected articles. A public reference manager (www.mendeley.com was used to delete duplicate articles.Results: An initial literature search yielded 134 references (www.pubmed.org: 53; www.scopus.com: 11; www.webofknowledge.com: 70. 15 publications were extracted based on the title for further analysis by two independent reviewers. Abstracts and whole articles were then reviewed to detect if they met inclusion criteria.Conclusions: The revised literature comprised 4 clinical studies and an in vitro and three in vivo reports. Overall, the results showed that tendon structure and properties after detraining are compromised, with an alteration in the tissue structural organization and mechanical properties. Clinical studies usually showed a lesser extent of tendon alterations, probably because preclinical studies permit an in-depth evaluation of tendon modifications, which is hard to perform in human subjects. In conclusion, after a period of sudden detraining (e.g. after an injury, physical activity

  3. p38 MAPK signaling in postnatal tendon growth and remodeling.

    Directory of Open Access Journals (Sweden)

    Andrew J Schwartz

    Full Text Available Tendon is a dynamic tissue whose structure and function is influenced by mechanical loading, but little is known about the fundamental mechanisms that regulate tendon growth and remodeling in vivo. Data from cultured tendon fibroblasts indicated that the p38 MAPK pathway plays an important role in tendon fibroblast proliferation and collagen synthesis in vitro. To gain greater insight into the mechanisms of tendon growth, and explore the role of p38 MAPK signaling in this process, we tested the hypotheses that inducing plantaris tendon growth through the ablation of the synergist Achilles tendon would result in rapid expansion of a neotendon matrix surrounding the original tendon, and that treatment with the p38 MAPK inhibitor SB203580 would prevent this growth. Rats were treated with vehicle or SB203580, and subjected to synergist ablation by bilateral tenectomy of the Achilles tendon. Changes in histological and biochemical properties of plantaris tendons were analyzed 3, 7, or 28 days after overload, and comparisons were made to non-overloaded animals. By 28 days after overload, tendon mass had increased by 30% compared to non-overloaded samples, and cross-sectional area (CSA increased by around 50%, with most of the change occurring in the neotendon. The expansion in CSA initially occurred through the synthesis of a hyaluronic acid rich matrix that was progressively replaced with mature collagen. Pericytes were present in areas of active tendon growth, but never in the original tendon ECM. Inhibition of p38 MAPK resulted in a profound decrease in IL6 expression, and had a modest effect on the expression of other ECM and cell proliferation genes, but had a negligible impact on overall tendon growth. The combined results from this study provided novel insights into tendon mechanobiology, and suggest that p38 MAPK signaling does not appear to be necessary for tendon growth in vivo.

  4. Flexor digitorum profundus tendon anatomy in the forearm

    Directory of Open Access Journals (Sweden)

    Teoman Dogan

    2012-04-01

    Methods: We used 11 forearms belonging to cadavers and fixed with formaldehyde. The forearms numbered 1, 2, 8, 9, 10, 11 were the left and right arms of the same cadavers. Those numbered 3, 4, 5, 6, 7 belonged to different cadavers. Dissections were made by using the atraumatic surgical technique. The tendons were studied to identify the structure and number of the fibers forming them. Results: The presence of a large common tendon was found in 10 of the 11 forearms. In 4 of these, the common tendon included the tendons of all four fingers. While the common tendon included 3 fingers in four forearms, it only included tendons belonging to 2 fingers in two forearms. It was not possible in one forearm to separate the common tendon into its fibers. In another forearm, tendons belonging to each digit were separate and independent starting at the muscle-tendon junction to the attachment points. Conclusion: The majority of the cadaver forearms used in the study displayed a single large FDP tendon in the zone between the muscle-tendon joint to the carpal tunnel entry prior to being distributed into each index. This anatomical feature should be considered in choosing materials and surgical technique for Zone V FDP tendon injuries, as well as in planning the rehabilitation process. [Hand Microsurg 2012; 1(1.000: 25-29

  5. Plantar tendons of the foot: MR imaging and US.

    Science.gov (United States)

    Donovan, Andrea; Rosenberg, Zehava Sadka; Bencardino, Jenny T; Velez, Zoraida Restrepo; Blonder, David B; Ciavarra, Gina A; Adler, Ronald Steven

    2013-01-01

    Tendon disorders along the plantar aspect of the foot may lead to significant symptoms but are often clinically misdiagnosed. Familiarity with the normal anatomy of the plantar tendons and its appearance at magnetic resonance (MR) imaging and ultrasonography (US) is essential for recognizing plantar tendon disorders. At MR imaging, the course of the plantar tendons is optimally visualized with dedicated imaging of the midfoot and forefoot. This imaging should include short-axis images obtained perpendicular to the long axis of the metatarsal shafts, which allows true cross-sectional evaluation of the plantar tendons. Normal plantar tendons appear as low-signal-intensity structures with all MR sequences. At US, accurate evaluation of the tendons requires that the ultrasound beam be perpendicular to the tendon. The normal tendon appears as a compact linear band of echogenic tissue that contains a fine, mixed hypoechoic and hyperechoic internal fibrillar pattern. Tendon injuries can be grouped into six major categories: tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, and instability (subluxation or dislocation) and can be well assessed with both MR imaging and US. The radiologist plays an important role in the diagnosis of plantar tendon disorders, and recognizing their imaging appearances at MR imaging and US is essential.

  6. [Flexor tendon repair: a short story].

    Science.gov (United States)

    Moutet, F; Corcella, D; Forli, A; Mesquida, V

    2014-12-01

    This short story of flexor tendon repair aims to illustrate hesitations and wanderings of this surgery. Obviously tendon repair was very early considered, but it developed and diffused rather lately. It became a routine practice only in 20th century. This was due on the one hand, in Occident, to the Galen's dogmatic interdiction, on the other hand, to the repair difficulties of this paradoxical structure. Actually tendon is made of fibroblasts and collagen (sticky substances), and then its only goal is to move. According to this necessity, whatever the used techniques are, gliding is the final purpose. Technical evolutions are illustrated by historical contributions to flexor tendon surgery of several "giants" of hand surgery. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  7. Extensor Tendon Injuries

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Extensor Tendon Injuries Email to a friend * required ...

  8. Sex Hormones and Tendon

    DEFF Research Database (Denmark)

    Hansen, Mette; Kjaer, Michael

    2016-01-01

    The risk of overuse and traumatic tendon and ligament injuries differ between women and men. Part of this gender difference in injury risk is probably explained by sex hormonal differences which are specifically distinct during the sexual maturation in the teenage years and during young adulthood....... The effects of the separate sex hormones are not fully elucidated. However, in women, the presence of estrogen in contrast to very low estrogen levels may be beneficial during regular loading of the tissue or during recovering after an injury, as estrogen can enhance tendon collagen synthesis rate. Yet...... has also been linked to a reduced responsiveness to relaxin. The present chapter will focus on sex difference in tendon injury risk, tendon morphology and tendon collagen turnover, but also on the specific effects of estrogen and androgens....

  9. Percutaneous tenotomy: development of a novel, percutaneous, ultrasound-guided needle-cutting technique for division of tendons and other connective tissue structures

    International Nuclear Information System (INIS)

    Hopkins, James; Sampson, Matthew

    2014-01-01

    A variety of surgical procedures derive therapeutic benefit from the division of retinacular, ligamentous or tendinous structures. Examples include carpal tunnel release for median nerve impingement, annular pulley release for trigger finger and tendon division for spastic muscular contractures. Here, using an animal cadaveric model, we describe the first steps in determining the feasibility of a novel, percutaneous, ultrasound-guided needle-cutting technique to achieve the same ends. The technique we describe involves the creation of an effective needle tenotomy device via a simple modification to an 18G coaxial, beveled needle. The technique holds promise for the development of a minimally invasive alternative approach that utilises readily available technology and equipment with minimisation of morbidity and cost associated with open procedures.

  10. Long bicipital tendon of the shoulder: normal anatomy and pathologic findings on MR imaging.

    Science.gov (United States)

    Erickson, S J; Fitzgerald, S W; Quinn, S F; Carrera, G F; Black, K P; Lawson, T L

    1992-05-01

    The tendon of the long head of the biceps muscle (long bicipital tendon) has a complex course from its muscle belly to its insertion onto the supraglenoid tubercle/glenoid labrum. It is stabilized by numerous tendinous and ligamentous structures and is, in turn, partly responsible for maintenance of normal glenohumeral function. In this report we describe the anatomy of this tendon, correlating high-resolution MR images with cryomicrotome sections. We illustrate typical MR findings in pathologic conditions affecting the long bicipital tendon sheath, the substance of the tendon, and finally the tendon position.

  11. A passive exoskeleton with artificial tendons: design and experimental evaluation.

    Science.gov (United States)

    van Dijk, Wietse; van der Kooij, Herman; Hekman, Edsko

    2011-01-01

    We developed a passive exoskeleton that was designed to minimize joint work during walking. The exoskeleton makes use of passive structures, called artificial tendons, acting in parallel with the leg. Artificial tendons are elastic elements that are able to store and redistribute energy over the human leg joints. The elastic characteristics of the tendons have been optimized to minimize the mechanical work of the human leg joints. In simulation the maximal reduction was 40 percent. The performance of the exoskeleton was evaluated in an experiment in which nine subjects participated. Energy expenditure and muscle activation were measured during three conditions: Normal walking, walking with the exoskeleton without artificial tendons, and walking with the exoskeleton with the artificial tendons. Normal walking was the most energy efficient. While walking with the exoskeleton, the artificial tendons only resulted in a negligibly small decrease in energy expenditure. © 2011 IEEE

  12. Tendon 'turnover lengthening' technique.

    Science.gov (United States)

    Cerovac, S; Miranda, B H

    2013-11-01

    Tendon defect reconstruction is amongst the most technically challenging areas in hand surgery. Tendon substance deficiency reconstruction techniques include lengthening, grafting, two-stage reconstruction and tendon transfers, however each is associated with unique challenges over and above direct repair. We describe a novel 'turnover lengthening' technique for hand tendons that has successfully been applied to the repair of several cases, including a case of attritional flexor and traumatic extensor tendon rupture in two presented patients where primary tenorrhaphy was not possible. In both cases a good post-operative outcome was achieved, as the patients were happy having returned back to normal activities of daily living such that they were discharged 12 weeks post-operatively. Our technique avoids the additional morbidity and complications associated with grafting, transfers and two stage reconstructions. It is quick, simple and reproducible for defects not exceeding 3-4 cm, provides a means of immediate one stage reconstruction, no secondary donor site morbidity and does not compromise salvage by tendon transfer and/or two-stage reconstruction in cases of failure. To our knowledge no such technique has been previously been described to reconstruct such hand tendon defects. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  13. Initial experience with visualizing hand and foot tendons by dual-energy computed tomography.

    Science.gov (United States)

    Deng, Kai; Sun, Cong; Liu, Cheng; Ma, Rui

    2009-01-01

    To assess the feasibility of visualizing hand and foot tendons by dual-energy computed tomography (CT). Twenty patients who suffered from hand or feet pains were scanned on dual-source CT (Definition, Forchheim, Germany) with dual-energy mode at tube voltages of 140 and 80 kV and a corresponding ratio of 1:4 between tube currents. The reconstructed images were postprocessed by volume rendering techniques (VRT) and multiplanar reconstruction (MPR). All of the suspected lesions were confirmed by surgery or follow-up studies. Twelve patients (total of 24 hands and feet, respectively) were found to be normal and the other eight patients (total of nine hands and feet, respectively) were found abnormal. Dual-energy techniques are very useful in visualizing tendons of the hands and feet, such as flexor pollicis longus tendon, flexor digitorum superficialis/profundus tendon, Achilles tendon, extensor hallucis longus tendon, and extensor digitorum longus tendon, etc. It can depict the whole shape of the tendons and their fixation points clearly. Peroneus longus tendon in the sole of the foot was not displayed very well. The distal ends of metacarpophalangeal joints with extensor digitoium tendon and extensor pollicis longus tendon were poorly shown. The lesions of tendons such as the circuitry, thickening, and adherence were also shown clearly. Dual-energy CT offers a new method to visualize tendons of the hand and foot. It could clearly display both anatomical structures and pathologic changes of hand and foot tendons.

  14. Achilles tendon healing

    International Nuclear Information System (INIS)

    Dillon, E.H.; Pope, C.F.; Barber, V.; Jokl, P.; Lynch, K.

    1990-01-01

    This paper reports on symptomatic Achilles tendon abnormalities (rupture, tendinitis) evaluated with MR imaging during the healing phase after either surgical or conservative treatment. A total of 21 patients were studied. Fifteen of 21 underwent surgery (13 tendon ruptures) and six were managed conservatively (one rupture). MR studies were obtained before treatment in 11, at 3 months in eight, at 6 months in seven, and at 12 months in 12. The 1.5-T spin-echo and gradient-echo images were correlated with clinical results, planter reflex response times, and calf force measurements. Sequential T2 times were obtained from representative levels in the tendons

  15. Achilles tendon repair

    Science.gov (United States)

    ... your Achilles tendon to point your toes and push off your foot when walking. If your Achilles ... MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine: Principles and Practice . 4th ed. Philadelphia, PA: ...

  16. Achilles Tendon Rupture

    Science.gov (United States)

    ... is a strong fibrous cord that connects the muscles in the back of your calf to your heel bone. If you overstretch your Achilles tendon, it can tear (rupture) completely or just partially. If your Achilles ...

  17. Mechanical Coupling between Muscle-Tendon Units Reduces Peak Stresses

    NARCIS (Netherlands)

    Maas, Huub; Finni, Taija

    2018-01-01

    The presence of mechanical linkages between synergistic muscles and their common tendons may distribute forces among the involved structures. We review studies, using humans and other animals, examining muscle and tendon interactions and discuss the hypothesis that connections between muscle bellies

  18. Tendon synovial cells secrete fibronectin in vivo and in vitro

    International Nuclear Information System (INIS)

    Banes, A.J.; Link, G.W.; Bevin, A.G.; Peterson, H.D.; Gillespie, Y.; Bynum, D.; Watts, S.; Dahners, L.

    1988-01-01

    The chemistry and cell biology of the tendon have been largely overlooked due to the emphasis on collagen, the principle structural component of the tendon. The tendon must not only transmit the force of muscle contraction to bone to effect movement, but it must also glide simultaneously over extratendonous tissues. Fibronectin is classified as a cell attachment molecule that induces cell spreading and adhesion to substratum. The external surface of intact avian flexor tendon stained positively with antibody to cellular fibronectin. However, if the surface synovial cells were first removed with collagenase, no positive reaction with antifibronectin antibody was detected. Analysis of immunologically stained frozen sections of tendon also revealed fibronectin at the tendon synovium, but little was associated with cells internal in tendon. The staining pattern with isolated, cultured synovial cells and fibroblasts from the tendon interior substantiated the histological observations. Analysis of polyacrylamide gel profiles of 35 S-methionine-labeled proteins synthesized by synovial cells and internal fibroblasts indicated that fibronectin was synthesized principally by synovial cells. Fibronectin at the tendon surface may play a role in cell attachment to prevent cell removal by the friction of gliding. Alternatively, fibronectin, with its binding sites for hyaluronic acid and collagen, may act as a complex for boundary lubrication

  19. Specialisation of extracellular matrix for function in tendons and ligaments

    Science.gov (United States)

    Birch, Helen L.; Thorpe, Chavaunne T.; Rumian, Adam P.

    2013-01-01

    Summary Tendons and ligaments are similar structures in terms of their composition, organisation and mechanical properties. The distinction between them stems from their anatomical location; tendons form a link between muscle and bone while ligaments link bones to bones. A range of overlapping functions can be assigned to tendon and ligaments and each structure has specific mechanical properties which appear to be suited for particular in vivo function. The extracellular matrix in tendon and ligament varies in accordance with function, providing appropriate mechanical properties. The most useful framework in which to consider extracellular matrix differences therefore is that of function rather than anatomical location. In this review we discuss what is known about the relationship between functional requirements, structural properties from molecular to gross level, cellular gene expression and matrix turnover. The relevance of this information is considered by reviewing clinical aspects of tendon and ligament repair and reconstructive procedures. PMID:23885341

  20. Longitudinal Long-term Magnetic Resonance Imaging and Clinical Follow-up After Single-Row Arthroscopic Rotator Cuff Repair: Clinical Superiority of Structural Tendon Integrity.

    Science.gov (United States)

    Heuberer, Philipp R; Smolen, Daniel; Pauzenberger, Leo; Plachel, Fabian; Salem, Sylvia; Laky, Brenda; Kriegleder, Bernhard; Anderl, Werner

    2017-05-01

    The number of arthroscopic rotator cuff surgeries is consistently increasing. Although generally considered successful, the reported number of retears after rotator cuff repair is substantial. Short-term clinical outcomes are reported to be rarely impaired by tendon retears, whereas to our knowledge, there is no study documenting long-term clinical outcomes and tendon integrity after arthroscopic rotator cuff repair. To investigate longitudinal long-term repair integrity and clinical outcomes after arthroscopic rotator cuff reconstruction. Case series; Level of evidence, 4. Thirty patients who underwent arthroscopic rotator cuff repair with suture anchors for a full-tendon full-thickness tear of the supraspinatus or a partial-tendon full-thickness tear of the infraspinatus were included. Two and 10 years after initial arthroscopic surgery, tendon integrity was analyzed using magnetic resonance imaging (MRI). The University of California, Los Angeles (UCLA) score and Constant score as well as subjective questions regarding satisfaction with the procedure and return to normal activity were used to evaluate short- and long-term outcomes. At the early MRI follow-up, 42% of patients showed a full-thickness rerupture, while 25% had a partial rerupture, and 33% of tendons remained intact. The 10-year MRI follow-up (129 ± 11 months) showed 50% with a total rerupture, while the other half of the tendons were partially reruptured (25%) or intact (25%). The UCLA and Constant scores significantly improved from preoperatively (UCLA total: 50.6% ± 20.2%; Constant total: 44.7 ± 10.5 points) to 2 years (UCLA total: 91.4% ± 16.0% [ P rotator cuff repair showed good clinical long-term results despite a high rate of retears. Nonetheless, intact tendons provided significantly superior clinical long-term outcomes, making the improvement of tendon healing and repair integrity important goals of future research efforts.

  1. Tendon injury and repair - A perspective on the basic mechanisms of tendon disease and future clinical therapy

    NARCIS (Netherlands)

    Snedeker, J.G.; Foolen, J.

    2017-01-01

    Tendon is an intricately organized connective tissue that efficiently transfers muscle force to the bony skeleton. Its structure, function, and physiology reflect the extreme, repetitive mechanical stresses that tendon tissues bear. These mechanical demands also lie beneath high clinical rates of

  2. [Achilles tendon rupture].

    Science.gov (United States)

    Thermann, H; Hüfner, T; Tscherne, H

    2000-03-01

    The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques.

  3. Tendon allograft sterilized by peracetic acid/ethanol combined with gamma irradiation.

    Science.gov (United States)

    Zhou, Mo; Zhang, Naili; Liu, Xiaoming; Li, Youchen; Zhang, Yumin; Wang, Xusheng; Li, Baoming; Li, Baoxing

    2014-07-01

    Research and clinical applications have demonstrated that the effects of tendon allografts are comparable to those of autografts when reconstructing injured tendons or ligaments, but allograft safety remains problematic. Sterilisation could eliminate or decrease the possibility of disease transmission, but current methods seldom achieve satisfactory sterilisation without affecting the mechanical properties of the tendon. Peracetic acid-ethanol in combination with low-dose gamma irradiation (PE-R) would inactivate potential deleterious microorganisms without affecting mechanical and biocompatible properties of tendon allograft. Controlled laboratory design. HIV, PPV, PRV and BVDV inactivation was evaluated. After verifying viral inactivation, the treated tendon allografts were characterised by optical microscopy, scanning electron microscopy and tensile testing, and the cytocompatibility was assessed with an MTT assay and by subcutaneous implantation. Effective and efficient inactivation of HIV, PPV, PRV and BVDV was observed. Histological structure and ultrastructure were unchanged in the treated tendon allograft, which also exhibited comparable biomechanical properties and good biocompatibility. The preliminary results confirmed our hypothesis and demonstrated that the PE-R tendon allograft has significant potential as an alternative to ligament/tendon reconstruction. Tendon allografts have been extensively used in ligament reconstruction and tendon repair. However, current sterilisation methods have various shortcomings, so PE-R has been proposed. This study suggests that PE-R tendon allograft has great potential as an alternative for ligament/tendon reconstruction. Sterilisation has been a great concern for tendon allografts. However, most sterilisation methods cannot inactivate viruses and bacteria without impairing the mechanical properties of the tendon allograft. Peracetic acid/ethanol with gamma irradiation can effectively inactivate viruses and bacteria

  4. Clinical aspects of tendon healing

    NARCIS (Netherlands)

    J.C.H.M. van der Meulen (Jacques)

    1974-01-01

    textabstractWe know that healing of a tendon wound takes place by an invasion of fibreblasts from the surrounding tissues; the tendon itself has no intrinsic healing capacity. lt was Potenza (1962) who proved that a traumatic suture of the tendons within their sheath is followed by disintegration of

  5. Stem Cell Applications in Tendon Disorders: A Clinical Perspective

    Directory of Open Access Journals (Sweden)

    Mark Young

    2012-01-01

    Full Text Available Tendon injuries are a common cause of morbidity and a significant health burden on society. Tendons are structural tissues connecting muscle to bone and are prone to tearing and tendinopathy, an overuse or degenerative condition that is characterized by failed healing and cellular depletion. Current treatments, for tendon tear are conservative, surgical repair or surgical scaffold reconstruction. Tendinopathy is treated by exercises, injection therapies, shock wave treatments or surgical tendon debridement. However, tendons usually heal with fibrosis and scar tissue, which has suboptimal tensile strength and is prone to reinjury, resulting in lifestyle changes with activity restriction. Preclinical studies show that cell therapies have the potential to regenerate rather than repair tendon tissue, a process termed tenogenesis. A number of different cell lines, with varying degrees of differentiation, have being evaluated including stem cells, tendon derived cells and dermal fibroblasts. Even though cellular therapies offer some potential in treating tendon disorders, there have been few published clinical trials to determine the ideal cell source, the number of cells to administer, or the optimal bioscaffold for clinical use.

  6. Flexor Tendon Injuries

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... fields From * To * DESCRIPTION The muscles that bend (flex) the fingers are called flexor ...

  7. triceps tendon avulsion

    African Journals Online (AJOL)

    GB

    2014-01-01

    Jan 1, 2014 ... trauma. Systemic causes such as chronic renal failure, steriod use, diabetes mellitus, hyperparathyroidism, rheumatoid arthritis, osteogensis imperfecta and local causes like local steriod injection, olecranon bursitis and attritional changes due to degenerative arthritis are associated with tendon weakening.

  8. Tendon material properties vary and are interdependent among turkey hindlimb muscles.

    Science.gov (United States)

    Matson, Andrew; Konow, Nicolai; Miller, Samuel; Konow, Pernille P; Roberts, Thomas J

    2012-10-15

    The material properties of a tendon affect its ability to store and return elastic energy, resist damage, provide mechanical feedback and amplify or attenuate muscle power. While the structural properties of a tendon are known to respond to a variety of stimuli, the extent to which material properties vary among individual muscles remains unclear. We studied the tendons of six different muscles in the hindlimb of Eastern wild turkeys to determine whether there was variation in elastic modulus, ultimate tensile strength and resilience. A hydraulic testing machine was used to measure tendon force during quasi-static lengthening, and a stress-strain curve was constructed. There was substantial variation in tendon material properties among different muscles. Average elastic modulus differed significantly between some tendons, and values for the six different tendons varied nearly twofold, from 829±140 to 1479±106 MPa. Tendons were stretched to failure, and the stress at failure, or ultimate tensile stress, was taken as a lower-limit estimate of tendon strength. Breaking tests for four of the tendons revealed significant variation in ultimate tensile stress, ranging from 66.83±14.34 to 112.37±9.39 MPa. Resilience, or the fraction of energy returned in cyclic length changes was generally high, and one of the four tendons tested was significantly different in resilience from the other tendons (range: 90.65±0.83 to 94.02±0.71%). An analysis of correlation between material properties revealed a positive relationship between ultimate tensile strength and elastic modulus (r(2)=0.79). Specifically, stiffer tendons were stronger, and we suggest that this correlation results from a constrained value of breaking strain, which did not vary significantly among tendons. This finding suggests an interdependence of material properties that may have a structural basis and may explain some adaptive responses observed in studies of tendon plasticity.

  9. Different Achilles Tendon Pathologies Show Distinct Histological and Molecular Characteristics

    Directory of Open Access Journals (Sweden)

    Franka Klatte-Schulz

    2018-01-01

    Full Text Available Reasons for the development of chronic tendon pathologies are still under debate and more basic knowledge is needed about the different diseases. The aim of the present study was therefore to characterize different acute and chronic Achilles tendon disorders. Achilles tendon samples from patients with chronic tendinopathy (n = 7, chronic ruptures (n = 6, acute ruptures (n = 13, and intact tendons (n = 4 were analyzed. The histological score investigating pathological changes was significantly increased in tendinopathy and chronic ruptures compared to acute ruptures. Inflammatory infiltration was detected by immunohistochemistry in all tendon pathology groups, but was significantly lower in tendinopathy compared to chronic ruptures. Quantitative real-time PCR (qRT-PCR analysis revealed significantly altered expression of genes related to collagens and matrix modeling/remodeling (matrix metalloproteinases, tissue inhibitors of metalloproteinases in tendinopathy and chronic ruptures compared to intact tendons and/or acute ruptures. In all three tendon pathology groups markers of inflammation (interleukin (IL 1β, tumor necrosis factor α, IL6, IL10, IL33, soluble ST2, transforming growth factor β1, cyclooxygenase 2, inflammatory cells (cluster of differentaition (CD 3, CD68, CD80, CD206, fat metabolism (fatty acid binding protein 4, peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, adiponectin, and innervation (protein gene product 9.5, growth associated protein 43, macrophage migration inhibitory factor were detectable, but only in acute ruptures significantly regulated compared to intact tendons. The study gives an insight into structural and molecular changes of pathological processes in tendons and might be used to identify targets for future therapy of tendon pathologies.

  10. Rotator cuff tendon connections with the rotator cable.

    Science.gov (United States)

    Rahu, Madis; Kolts, Ivo; Põldoja, Elle; Kask, Kristo

    2017-07-01

    The literature currently contains no descriptions of the rotator cuff tendons, which also describes in relation to the presence and characteristics of the rotator cable (anatomically known as the ligamentum semicirculare humeri). The aim of the current study was to elucidate the detailed anatomy of the rotator cuff tendons in association with the rotator cable. Anatomic dissection was performed on 21 fresh-frozen shoulder specimens with an average age of 68 years. The rotator cuff tendons were dissected from each other and from the glenohumeral joint capsule, and the superior glenohumeral, coracohumeral, coracoglenoidal and semicircular (rotator cable) ligaments were dissected. Dissection was performed layer by layer and from the bursal side to the joint. All ligaments and tendons were dissected in fine detail. The rotator cable was found in all specimens. It was tightly connected to the supraspinatus (SSP) tendon, which was partly covered by the infraspinatus (ISP) tendon. The posterior insertion area of the rotator cable was located in the region between the middle and inferior facets of the greater tubercle of the humerus insertion areas for the teres minor (TM), and ISP tendons were also present and fibres from the SSP extended through the rotator cable to those areas. The connection between the rotator cable and rotator cuff tendons is tight and confirms the suspension bridge theory for rotator cuff tears in most areas between the SSP tendons and rotator cable. In its posterior insertion area, the rotator cable is a connecting structure between the TM, ISP and SSP tendons. These findings might explain why some patients with relatively large rotator cuff tears can maintain seamless shoulder function.

  11. Evaluation of the equine digital flexor tendon sheath using diagnostic ultrasound and contrast radiography

    International Nuclear Information System (INIS)

    Redding, W.R.

    1994-01-01

    This study was designed to evaluate the normal anatomy of the digital flexor tendon sheath using contrast radiography and diagnostic ultrasound. Iodinated contrast medium was injected into eight cadaver limbs and the limbs immediately frozen. Lateromedial and dorsopalmar/plantar radiographs were made. These limps were then cut transversely and proximal to distal radiographs of each slab were made. This cross sectional contrast methodology allowed the visualization of the relative size and shape of the superficial and deep digital flexor tendons as well as the potential space taken by effusions of the digital flexor tendon sheath. The second part of the study used twelve live animals with normal digital flexor tendon sheaths. Ultrasonographic measurement of the structures of the digital flexor tendon sheath at each level were compiled. This documented the ability of diagnostic ultrasound to image: 1) the superficial and deep digital flexor tendons, 2) the proximal and distal ring of the manica flexoria, 3) the straight and oblique sesamoidean ligaments, and 4) the mesotendinous attachments to the superficial and deep flexor tendons. Iodinated contrast medium was then injected into the digital flexor tendon sheath and the ultrasonography repeated. These images were compared with those obtained from contrast radiography and prosections of twenty normal limbs. The iodinated contrast medium enhanced sonographic imaging of the structures of the digital tendon sheath, particularly the abaxial borders of the superficial digital flexor tendon branches and the mesotendinous attachments to the superficial and deep digital flexor tendons

  12. Increased muscle belly and tendon stiffness in patients with Parkinson's disease, as measured by myotonometry.

    Science.gov (United States)

    Marusiak, Jarosław; Jaskólska, Anna; Budrewicz, Sławomir; Koszewicz, Magdalena; Jaskólski, Artur

    2011-09-01

    Based on Davis's law, greater tonus of the muscle belly in individuals with Parkinson's disease can create greater tension in the tendon, leading to structural adjustment and an increase in tendon stiffness. Our study aimed to separately assess passive stiffness in the muscle belly and tendon in medicated patients with Parkinson's disease, using myotonometry. We tested 12 patients with Parkinson's disease and 12 healthy matched controls. Passive stiffness of muscle belly and tendon was estimated by myotonometry, electromyography, and mechanomyography in relaxed biceps and triceps brachii muscles. Compared with controls, patients with Parkinson's disease had higher stiffness in the muscle belly and tendon of the biceps brachii and in the tendon of the triceps brachii. In patients with Parkinson's disease, there was a positive correlation between muscle belly stiffness and parkinsonian rigidity in the biceps brachii. Patients with Parkinson's disease have higher passive stiffness of the muscle belly and tendon than healthy matched controls. Copyright © 2011 Movement Disorder Society.

  13. Miscellaneous conditions of tendons, tendon sheaths, and ligaments.

    Science.gov (United States)

    Dyson, S J; Dik, K J

    1995-08-01

    The use of diagnostic ultrasonography has greatly enhances our ability to diagnose injuries of tendons and tendon sheaths that were previously either unrecognized or poorly understood. For may of these injuries, there is currently only a small amount of follow-up data. This article considers injuries of the deep digital flexor tendon and its accessory ligament, the carpal tunnel syndrome soft tissue swellings on the dorsal aspect of the carpus, intertubercular (bicipital) bursitis and bicipital tendinitis, injuries of the gastrocnemius tendon, common calcaneal tendinitis, rupture of peroneus (fibularis tertius) and ligaments injuries of the back.

  14. In vitro tendon tissue development from human fibroblasts demonstrates collagen fibril diameter growth associated with a rise in mechanical strength

    DEFF Research Database (Denmark)

    Herchenhan, Andreas; Bayer, Monika L; Svensson, René B

    2013-01-01

    Collagen-rich tendons and ligaments are important for joint stability and force transmission, but the capacity to form new tendon is poorly understood. In the present study, we investigated mechanical strength, fibril size, and structure during development of tendon-like tissue from adult human...

  15. The initiation of embryonic-like collagen fibrillogenesis by adult human tendon fibroblasts when cultured under tension

    DEFF Research Database (Denmark)

    Bayer, Monika L; Yeung, Chin-Yan C; Kadler, Karl E

    2010-01-01

    Tendon fibroblasts synthesize collagen and form fibrils during embryonic development, but to what extent mature fibroblasts are able to recapitulate embryonic development and develop normal tendon structure is unknown. The present study examined the capability of mature human tendon fibroblasts t...

  16. Fascicles and the interfascicular matrix show decreased fatigue life with ageing in energy storing tendons.

    Science.gov (United States)

    Thorpe, Chavaunne T; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2017-07-01

    Tendon is composed of rope-like fascicles bound together by interfascicular matrix (IFM). The IFM is critical for the function of energy storing tendons, facilitating sliding between fascicles to allow these tendons to cyclically stretch and recoil. This capacity is required to a lesser degree in positional tendons. We have previously demonstrated that both fascicles and IFM in energy storing tendons have superior fatigue resistance compared with positional tendons, but the effect of ageing on the fatigue properties of these different tendon subunits has not been determined. Energy storing tendons become more injury-prone with ageing, indicating reduced fatigue resistance, hence we tested the hypothesis that the decline in fatigue life with ageing in energy storing tendons would be more pronounced in the IFM than in fascicles. We further hypothesised that tendon subunit fatigue resistance would not alter with ageing in positional tendons. Fascicles and IFM from young and old energy storing and positional tendons were subjected to cyclic fatigue testing until failure, and mechanical properties were calculated. The results show that both IFM and fascicles from the SDFT exhibit a similar magnitude of reduced fatigue life with ageing. By contrast, the fatigue life of positional tendon subunits was unaffected by ageing. The age-related decline in fatigue life of tendon subunits in energy storing tendons is likely to contribute to the increased risk of injury in aged tendons. Full understanding of the mechanisms resulting in this reduced fatigue life will aid in the development of treatments and interventions to prevent age-related tendinopathy. Understanding the effect of ageing on tendon-structure function relationships is crucial for the development of effective preventative measures and treatments for age-related tendon injury. In this study, we demonstrate for the first time that the fatigue resistance of the interfascicular matrix decreases with ageing in energy

  17. Grouting aid for controlling the separation of water for cement grout for grouting vertical tendons in nuclear concrete pressure vessels

    International Nuclear Information System (INIS)

    Schupack, M.

    1976-01-01

    Considerable testing and development work has led to grouting procedures which can successfully grout 60 m and taller tendons in containment structures. The exaggerated water separation phenomena of strand tendons can be controlled by chemical admixtures using proper mixing and pumping procedures. Experience with both vertical six-bar tendons and large capacity strand type tendons are described. History, development work, characteristics of grout using the admixtures, mixing and pumping procedure, full scale tests and practical applications are included. (author)

  18. Simultaneous bilateral patellar tendon rupture ?

    OpenAIRE

    Moura, Diogo Lino; Marques, Jos? Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2016-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a s...

  19. Disorders of the long head of the biceps tendon.

    Science.gov (United States)

    Sethi, N; Wright, R; Yamaguchi, K

    1999-01-01

    Without a clear understanding of the functional role of the biceps tendon, treatment recommendations have been a subject of controversy. An objective review of the available information would suggest that some humeral head stability may be imparted through the tendon. However, the magnitude of this function is likely to be small and possibly insignificant. In contrast, the symptomatic significance of the long head of the biceps is less controversial, and it has become increasingly recognized as an important source of persistent shoulder pain when not specifically addressed. When present, persistent pain from the long head of the biceps is likely to have more negative functional consequences than loss of the tendon itself. Given these concerns, evaluation and treatment of patients with long head of the biceps disorders should be individualized, based on the likelihood that biceps-related pain will resolve. Although not universally accepted, we recommend tenodesis of the long head of the biceps in those cases in which there are either chronic inflammatory or structural changes, which would make it unlikely that the pain would resolve. These clinical situations in which tenodesis would be required include greater than 25% partial thickness tearing of the tendon, chronic atrophic changes of the tendon, any luxation of the biceps tendon from the bicipital groove, any disruption of associated bony or ligamentous anatomy of the bicipital groove that would make autotenodesis likely (i.e., 4-part fracture), and any significant reduction or atrophy of the size of the tendon that is more than 25% of the normal tendon width. Relative indications for biceps tenodesis also include biceps disease in the context of a failed decompression for rotator cuff tendinitis. It should be emphasized that routine tenodesis is not recommended during operative treatment for the rotator cuff. Rather, we avoid tenodesis whenever it is believed that inflammatory changes to the biceps tendon are

  20. Repair of Achilles tendon defect with autologous ASCs engineered tendon in a rabbit model.

    Science.gov (United States)

    Deng, Dan; Wang, Wenbo; Wang, Bin; Zhang, Peihua; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin; Liu, Wei

    2014-10-01

    Adipose derived stem cells (ASCs) are an important cell source for tissue regeneration and have been demonstrated the potential of tenogenic differentiation in vitro. This study explored the feasibility of using ASCs for engineered tendon repair in vivo in a rabbit Achilles tendon model. Total 30 rabbits were involved in this study. A composite tendon scaffold composed of an inner part of polyglycolic acid (PGA) unwoven fibers and an outer part of a net knitted with PGA/PLA (polylactic acid) fibers was used to provide mechanical strength. Autologous ASCs were harvested from nuchal subcutaneous adipose tissues and in vitro expanded. The expanded ASCs were harvested and resuspended in culture medium and evenly seeded onto the scaffold in the experimental group, whereas cell-free scaffolds served as the control group. The constructs of both groups were cultured inside a bioreactor under dynamic stretch for 5 weeks. In each of 30 rabbits, a 2 cm defect was created on right side of Achilles tendon followed by the transplantation of a 3 cm cell-seeded scaffold in the experimental group of 15 rabbits, or by the transplantation of a 3 cm cell-free scaffold in the control group of 15 rabbits. Animals were sacrificed at 12, 21 and 45 weeks post-surgery for gross view, histology, and mechanical analysis. The results showed that short term in vitro culture enabled ASCs to produce matrix on the PGA fibers and the constructs showed tensile strength around 50 MPa in both groups (p > 0.05). With the increase of implantation time, cell-seeded constructs gradually form neo-tendon and became more mature at 45 weeks with histological structure similar to that of native tendon and with the presence of bipolar pattern and D-periodic structure of formed collagen fibrils. Additionally, both collagen fibril diameters and tensile strength increased continuously with significant difference among different time points (p tendon tissue with fibril structure observable only at 45 weeks

  1. Achilles tendon of wistar rats treated with laser therapy and eccentric exercise

    Directory of Open Access Journals (Sweden)

    Maria Verônica de Souza

    2015-10-01

    as a healthy tendon. On the other hand, it also does not influence negatively the structure and function of the Achilles tendon.

  2. Mineral distributions at the developing tendon enthesis.

    Science.gov (United States)

    Schwartz, Andrea G; Pasteris, Jill D; Genin, Guy M; Daulton, Tyrone L; Thomopoulos, Stavros

    2012-01-01

    Tendon attaches to bone across a functionally graded interface, "the enthesis". A gradient of mineral content is believed to play an important role for dissipation of stress concentrations at mature fibrocartilaginous interfaces. Surgical repair of injured tendon to bone often fails, suggesting that the enthesis does not regenerate in a healing setting. Understanding the development and the micro/nano-meter structure of this unique interface may provide novel insights for the improvement of repair strategies. This study monitored the development of transitional tissue at the murine supraspinatus tendon enthesis, which begins postnatally and is completed by postnatal day 28. The micrometer-scale distribution of mineral across the developing enthesis was studied by X-ray micro-computed tomography and Raman microprobe spectroscopy. Analyzed regions were identified and further studied by histomorphometry. The nanometer-scale distribution of mineral and collagen fibrils at the developing interface was studied using transmission electron microscopy (TEM). A zone (∼20 µm) exhibiting a gradient in mineral relative to collagen was detected at the leading edge of the hard-soft tissue interface as early as postnatal day 7. Nanocharacterization by TEM suggested that this mineral gradient arose from intrinsic surface roughness on the scale of tens of nanometers at the mineralized front. Microcomputed tomography measurements indicated increases in bone mineral density with time. Raman spectroscopy measurements revealed that the mineral-to-collagen ratio on the mineralized side of the interface was constant throughout postnatal development. An increase in the carbonate concentration of the apatite mineral phase over time suggested possible matrix remodeling during postnatal development. Comparison of Raman-based observations of localized mineral content with histomorphological features indicated that development of the graded mineralized interface is linked to endochondral

  3. CT of peroneal tendon injury in patients with calcaneal fractures

    International Nuclear Information System (INIS)

    Rosenberg, Z.S.; Feldman, F.; Singson, R.D.

    1986-01-01

    Injury to the peroneal tendons is a major complication of intraarticular calcaneal fractures. Heretofore, the injury has been difficult to diagnose by routine imaging modalities. However, CT studies of 24 intraarticular calcaneal fractures revealed evidence of peroneal tendon injury in 22 cases. The pathologic conditions included lateral displacement, subluxation, dislocation, and impingement on the tendons by bony fragments, hematomas, and scar tissue. Patients studied 6-12 months after injury had CT evidence consistent with clinical symptoms of peroneal tenosynovitis. Since peroneal tendon injury is surgically correctable, it should be differentiated from other known and more obvious complications, of calcaneal fractures. CT therefore serves as a valuable, noninvasive tool in evaluating these otherwise nonvisualized soft tissue structures in the immediate posttraumatic period as well as during long-term follow up

  4. Extracellular matrix adaptation of tendon and skeletal muscle to exercise

    DEFF Research Database (Denmark)

    Kjaer, Michael; Magnusson, Peter; Krogsgaard, Michael

    2006-01-01

    The extracellular matrix (ECM) of connective tissues enables linking to other tissues, and plays a key role in force transmission and tissue structure maintenance in tendons, ligaments, bone and muscle. ECM turnover is influenced by physical activity, and both collagen synthesis and metalloprotease......-beta and IL-6 is enhanced following exercise. For tendons, metabolic activity (e.g. detected by positron emission tomography scanning), circulatory responses (e.g. as measured by near-infrared spectroscopy and dye dilution) and collagen turnover are markedly increased after exercise. Tendon blood flow...... is regulated by cyclooxygenase-2 (COX-2)-mediated pathways, and glucose uptake is regulated by specific pathways in tendons that differ from those in skeletal muscle. Chronic loading in the form of physical training leads both to increased collagen turnover as well as to some degree of net collagen synthesis...

  5. Mechanoreceptors of the Achilles tendon: a histomorphological study in pigs with clinical significance for humans.

    Science.gov (United States)

    Kapetanakis, Stylianos; Gkasdaris, Grigorios; Daneva, Eleni; Givissis, Panagiotis; Papathanasiou, Jannis; Xanthos, Theodoros

    2017-01-01

    Tendons contain neurosensory elements called mechanoreceptors which contribute to the neuromuscular system as sources of reflex signals. The literature is lacking in histological assessment of mechanoreceptors of the Achilles tendon in piglets and our aim was to indicate their types, location and quantity. The study was performed using histological tissue samples from the Achilles tendon of ten healthy pigs, five left, five right, six males, four females. The samples were taken up to 12 hours after death. Immediately after removal, the tendons were placed in the laboratory where sections were taken and examined microscopically. The tendons were stained with the gold chloride method. The results showed that Golgi tendon organs, free nerve endings and Pacinian-like corpuscles were found in the Achilles tendon of pigs. Most structures were near the osteotendinous and myotendinous junctions, away from the middle portion of the tendon. As shown in other studies and similarly in ours, mechanoreceptors tend to be close to the distant thirds and not in the middle third of the tendon. This study could have clinical application on human Achilles tendon and its repair after damage. IV.

  6. Achillodynia. Radiological imaging of acute and chronic overuse injuries of the Achilles tendon

    International Nuclear Information System (INIS)

    Syha, R.; Springer, F.; Grosse, U.; Tuebingen Univ.; Ketelsen, D.; Kramer, U.; Horger, M.; Ipach, I.; Schick, F.

    2013-01-01

    In the past decades the incidence of acute and chronic disorders of the Achilles tendon associated with sport-induced overuse has steadily increased. Besides acute complete or partial ruptures, achillodynia (Achilles tendon pain syndrome), which is often associated with tendon degeneration, represents the most challenging entity regarding clinical diagnostics and therapy. Therefore, the use of imaging techniques to differentiate tendon disorders and even characterize structure alterations is of growing interest. This review article discusses the potential of different imaging techniques with respect to the diagnosis of acute and chronic tendon disorders. In this context, the most commonly used imaging techniques are magnetic resonance imaging (MRI), B-mode ultrasound, and color-coded Doppler ultrasound (US). These modalities allow the detection of acute tendon ruptures and advanced chronic tendon disorders. However, the main disadvantages are still the low capabilities in the detection of early-stage degeneration and difficulties in the assessment of treatment responses during follow-up examinations. Furthermore, differentiation between chronic partial ruptures and degeneration remains challenging. The automatic contour detection and texture analysis may allow a more objective and quantitative interpretation, which might be helpful in the monitoring of tendon diseases during follow-up examinations. Other techniques to quantify tendon-specific MR properties, e.g. based on ultrashort echo time (UTE) sequences, also seem to have great potential with respect to the precise detection of degenerative tendon disorders and their differentiation at a very early stage. (orig.)

  7. Non-linear finite element model to assess the effect of tendon forces on the foot-ankle complex.

    Science.gov (United States)

    Morales-Orcajo, Enrique; Souza, Thales R; Bayod, Javier; Barbosa de Las Casas, Estevam

    2017-11-01

    A three-dimensional foot finite element model with actual geometry and non-linear behavior of tendons is presented. The model is intended for analysis of the lower limb tendon forces effect in the inner foot structure. The geometry of the model was obtained from computational tomographies and magnetic resonance images. Tendon tissue was characterized with the first order Ogden material model based on experimental data from human foot tendons. Kinetic data was employed to set the load conditions. After model validation, a force sensitivity study of the five major foot extrinsic tendons was conducted to evaluate the function of each tendon. A synergic work of the inversion-eversion tendons was predicted. Pulling from a peroneus or tibialis tendon stressed the antagonist tendons while reducing the stress in the agonist. Similar paired action was predicted for the Achilles tendon with the tibialis anterior. This behavior explains the complex control motion performed by the foot. Furthermore, the stress state at the plantar fascia, the talocrural joint cartilage, the plantar soft tissue and the tendons were estimated in the early and late midstance phase of walking. These estimations will help in the understanding of the functional role of the extrinsic muscle-tendon-units in foot pronation-supination. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  8. Muscle-tendon-related abnormalities detected by ultrasonography are common in symptomatic hip dysplasia

    DEFF Research Database (Denmark)

    Jacobsen, Julie Sandell; Bolvig, Lars; Hölmich, Per

    2018-01-01

    INTRODUCTION: Hip dysplasia is characterized by reduced acetabular coverage of the femoral head leading to an increased mechanical load on the hip joint and the acting hip muscles. Potentially, the muscles and tendons functioning close to the hip joint may present with overuse......-related ultrasonography findings. The primary aim was to report the prevalence of muscle-tendon-related abnormalities detected by ultrasonography in 100 patients with symptomatic hip dysplasia. The secondary aim was to investigate correlations between muscle-tendon-related abnormalities detected by ultrasonography......-tendon-related abnormalities detected by ultrasonography in the hip and groin region are common in patients with symptomatic hip dysplasia, and the ultrasonography findings of the iliopsoas and gluteus medius/minimus tendons are weakly to moderately correlated to pain related to muscles and tendons in these structures. Both...

  9. The roles of TGF-beta1 gene transfer on collagen formation during Achilles tendon healing.

    Science.gov (United States)

    Hou, Yu; Mao, ZeBing; Wei, XueLei; Lin, Lin; Chen, LianXu; Wang, HaiJun; Fu, Xin; Zhang, JiYing; Yu, ChangLong

    2009-05-29

    Collagen content and cross-linking are believed to be major determinants of tendon structural integrity and function. The current study aimed to investigate the effects of transforming growth factor (TGF)-beta1 on the collagen content and cross-linking of Achilles tendons, and on the histological and biomechanical changes occurring during Achilles tendon healing in rabbits. Bone marrow-derived mesenchymal stem cells (BMSCs) transfected with the TGF-beta1 gene were surgically implanted into experimentally injured Achilles tendons. Collagen proteins were identified by immunohistochemical staining and fiber bundle accumulation was revealed by Sirius red staining. Achilles tendons treated with TGF-beta1-transfected BMSCs showed higher concentrations of collagen I protein, more rapid matrix remodeling, and larger fiber bundles. Thus TGF-beta1 can promote mechanical strength in healing Achilles tendons by regulating collagen synthesis, cross-link formation, and matrix remodeling.

  10. Insulin-like growth factor I enhances collagen synthesis in engineered human tendon tissue

    DEFF Research Database (Denmark)

    Herchenhan, Andreas; Bayer, Monika L.; Eliasson, Pernilla

    2015-01-01

    OBJECTIVE: Isolated human tendon cells form 3D tendon constructs that demonstrate collagen fibrillogenesis and feature structural similarities to tendon when cultured under tensile load. The exact role of circulating growth factors for collagen formation in tendon is sparsely examined. We...... investigated the influence of insulin-like growth factor I (IGF-I) on tendon construct formation in 3D cell culture. DESIGN: Tendon constructs were grown in 0.5 or 10% FBS with or without IGF-I (250 mg/ml) supplementation. Collagen content (fluorometric), mRNA levels (PCR) and fibril diameter (transmission...... electron microscopy) were determined at 7, 10, 14, 21 and 28 days. RESULTS: IGF-I revealed a stimulating effect on fibril diameter (up to day 21), mRNA for collagen (to day 28), tenomodulin (to day 28) and scleraxis (at days 10 and 14), and on overall collagen content. 10% FBS diminished the development...

  11. In vivo Evaluation of Patellar Tendon Stiffness in Individuals with Patellofemoral Pain Syndrome

    Directory of Open Access Journals (Sweden)

    Hsin-Yi Liu

    2008-01-01

    Full Text Available The objective of this study was to utilise an ultrasonic technique to assess the effect of patellofemoral pain syndrome (PFPS on the mechanical properties of the patellar tendon. Seven subjects with PFPS and seven matched control subjects volunteered to participate in this study. Subjects were asked to perform isometric maximal voluntary contractions of the knee extensors while their knee extension torque was monitored and the displacement of the patellar tendon was recorded with an ultrasonic system. Our results showed significantly lower tendon stiffness (by ∼30% in the PFPS subjects. Although tendon secant modulus was lower by 34% in the PFPS subjects, the difference was not statistically significant. Therefore, we conclude that the ultrasonic technique was able to detect a decrease in the structural stiffness of the patellar tendon associated with PFPS. The decrease in tendon stiffness was moderately correlated with the length of symptoms in these individuals.

  12. Bioreactor Design for Tendon/Ligament Engineering

    OpenAIRE

    Wang, Tao; Gardiner, Bruce S.; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B.; Wang, Allan; Xu, Jiake; Smith, David W.; Lloyd, David G.; Zheng, Ming H.

    2012-01-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a s...

  13. Simultaneous bilateral patellar tendon rupture.

    Science.gov (United States)

    Moura, Diogo Lino; Marques, José Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2017-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  14. Simultaneous bilateral patellar tendon rupture

    Directory of Open Access Journals (Sweden)

    Diogo Lino Moura

    Full Text Available ABSTRACT Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  15. [Experimental study on co-culture of human fibroblasts on decellularized Achilles tendon].

    Science.gov (United States)

    Wang, Zhibing; Zhang, Xia; Guo, Xinyu; Qin, Chuan

    2013-07-01

    To investigate the preparation of decellularized Achilles tendons and the effect of co-culture of human fibroblasts on the scaffold so as to provide a scaffold for the tissue engineered ligament reconstruction. Achilles tendons of both hind limbs were harvested from 10 male New Zealand white rabbits (5-month-old; weighing, 4-5 kg). The Achilles tendons were decellularized using trypsin, Triton X-100, and sodium dodecyl sulfate (SDS), and then gross observation, histological examination, and scanning electron microscope (SEM) observation were performed; the human fibroblasts were seeded on the decellularized Achilles tendon, and then cytocompatibility was tested using the cell counting kit 8 method at 1, 3, 5, 7, and 9 days after co-culture. At 4 weeks after co-culture, SEM, HE staining, and biomechanical test were performed for observing cell-scaffold composite, and a comparison was made with before and after decellularization. After decellularization, the tendons had integrated aponeurosis and enlarged volume with soft texture and good toughness; there was no loose connective tissue and tendon cells between tendon bundles, the collagen fibers arranged loosely with three-dimensional network structure and more pores between tendon bundles; and it had good cytocompatibility. At 4 weeks after co-culture, cells migrated into the pores, and three-dimensional network structure disappeared. By biomechanical test, the tensile strength and Young's elastic modulus of the decellularized Achilles tendon group decreased significantly when compared with normal Achilles tendons group and cell-scaffold composite group (P Achilles tendons group and cell-scaffold composite group (P > 0.05). There was no significant difference in elongation at break among 3 groups (P > 0.05). The decellularized Achilles tendon is biocompatible to fibroblasts. It is suit for the scaffold for tissue engineered ligament reconstruction.

  16. Fixation of the Achilles tendon insertion using suture button technology.

    Science.gov (United States)

    Fanter, Nathan J; Davis, Edward W; Baker, Champ L

    2012-09-01

    In the operative treatment of Achilles insertional tendinopathy, no guidelines exist concerning which form of fixation of the Achilles tendon insertion is superior. Transcalcaneal drill pin passage does not place any major plantar structures at risk, and the addition of a Krackow stitch and suture button to the fixation technique provides a significant increase in ultimate load to failure in Achilles tendon insertional repairs. Controlled laboratory study. The Achilles tendon insertions in 6 fresh-frozen cadaveric ankles were detached, and transcalcaneal drill pins were passed. Plantar dissection took place to evaluate the drill pin relationship to the plantar fascia, lateral plantar nerve and artery, flexor digitorum longus tendon, and master knot of Henry. The Achilles tendons were then repaired with a double-row suture anchor construct alone or with a suture button and Krackow stitch added to the double-row suture anchor construct. The repairs were then tested to maximum load to failure at 20 mm/min. The mode of failure was recorded, and the mean maximum load to failure was assessed using the Student t test for distributions with equal variance. Transcalcaneal drill pin passage did not place any selected anatomic structures at risk. The mean maximum load to failure for the suture bridge group was 239.2 N; it was 391.4 N for the group with the suture button (P = .014). The lateral plantar artery was the structure placed at greatest risk from drill pin placement, with a mean distance of 22.7 mm (range, 16.5-29.2 mm) between the pin and artery. In this laboratory study, transcalcaneal drill pin passage appeared to be anatomically safe, and the use of suture button technology with a Krackow stitch for Achilles tendon insertional repair significantly increased repair strength. Achilles tendon insertional repair with suture button fixation and a Krackow stitch may facilitate the earlier institution of postoperative rehabilitation and improve clinical outcomes.

  17. Testing of large prestressing tendon end anchorage regions

    International Nuclear Information System (INIS)

    Johnson, T.E.

    1976-01-01

    Tests were performed on concrete end anchorage regions for prestressing tendons with ultimate strengths of approximately 8,900 kN. One test structure simulated a full scale concrete containment buttress and the other two test specimens were concrete blocks. The behavior of the test structure and specimens, when subjected to loading, was monitored by strain gages and dial gages. The testing illustrated that all of the amounts of reinforcing tested should be acceptable for the end anchor zones of large tendons presently used in prestressed concrete containment structures. (author)

  18. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    Science.gov (United States)

    van Ark, M; Docking, S I; van den Akker-Scheek, I; Rudavsky, A; Rio, E; Zwerver, J; Cook, J L

    2016-02-01

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The critical tendon load that affects tendon structure is unknown. The aim of this study was to investigate patellar tendon structure on each day of a 5-day volleyball tournament in an adolescent population (16-18 years). The right patellar tendon of 41 players in the Australian Volleyball Schools Cup was scanned with ultrasound tissue characterization (UTC) on every day of the tournament (Monday to Friday). UTC can quantify structure of a tendon into four echo types based on the stability of the echo pattern. Generalized estimating equations (GEE) were used to test for change of echo type I and II over the tournament days. Participants played between eight and nine matches during the tournament. GEE analysis showed no significant change of echo type percentages of echo type I (Wald chi-square = 4.603, d.f. = 4, P = 0.331) and echo type II (Wald chi-square = 6.070, d.f. = 4, P = 0.194) over time. This study shows that patellar tendon structure of 16-18-year-old volleyball players is not affected during 5 days of cumulative loading during a volleyball tournament. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Tendon overuse syndrome: imaging diagnosis

    International Nuclear Information System (INIS)

    Huber, W.; Nehrer, S.; Muellner, T.; Kainberger, F.; Ulreich, N.; Bernhard, C.; Imhof, H.

    2001-01-01

    Injuries of muscles and tendons occur commonly during various sporting activities and in most cases the athletes feel such an accident to be sudden and unavoidable. The rupture of a tendon, however, has to be considered in many cases as the final stage of a long-standing progressive degeneration of collagen fibers. This process con be described as 'tendon overuse syndrome (TOS)'. Diagnostic imaging modalities, especially sonography and MRI, are suitable to detect and analyse the different stages of this syndrome and the degree of morphological abnormalities. The first stage is painful functional derangement, followed by tendovaginitis, peritendinitis, or bursitis. The third stage is tendinosis resulting from biomechanical or ischaemic injury of tendon fibers which may eventually be followed by partial or complete rupture. Regional or individual specifications of these four stages may occur at anatomically predisposing sites, so-called critical zones, or during periods of specific proneness, the vulnerable phases. (author)

  20. Arthrography of the biceps tendon

    International Nuclear Information System (INIS)

    Ahovuo, J.; Linden, H.; Hovi, I.; Paavolainen, P.; Bjoerkenheim, J.M.

    1988-01-01

    The purpose of this study was to analyse the factors having an influence on the arthrographic imaging of the biceps tendon. The study comprised 174 patients suffering from chronic shoulder pain. They underwent conventional shoulder arthrography with sodium meglumine metrizoate or metrizamide as a contrast medium. In the patients with a full-thickness tear of the rotator cuff, the biceps tendon sheath failed to fill with contrast medium more often than in those with an intact tendinous cuff. Metrizamide filled the biceps tendon sheath more readily than sodium meglumine metrizoate in patients with a full-thickness tear of the ortator cuff. The volume of the contrast medium injected had no influence on the imaging of the biceps tendon. (orig.)

  1. Does the adolescent patellar tendon respond to 5 days of cumulative load during a volleyball tournament?

    NARCIS (Netherlands)

    van Ark, M.; Docking, S.I.; van den Akker-Scheek, I.; Rudavsky, A.; Rio, E.; Zwerver, J.; Cook, J.L.

    Patellar tendinopathy (jumper's knee) has a high prevalence in jumping athletes. Excessive load on the patellar tendon through high volumes of training and competition is an important risk factor. Structural changes in the tendon are related to a higher risk of developing patellar tendinopathy. The

  2. Dynamic adaptation of tendon and muscle connective tissue to mechanical loading

    DEFF Research Database (Denmark)

    Mackey, Abigail; Heinemeier, Katja Maria; Koskinen, Satu Osmi Anneli

    2008-01-01

    The connective tissue of tendon and skeletal muscle is a crucial structure for force transmission. A dynamic adaptive capacity of these tissues in healthy individuals is evident from reports of altered gene expression and protein levels of the fibrillar and network-forming collagens, when subjected...... in this article provide strong evidence for the highly adaptable nature of connective tissue in muscle and tendon....

  3. In vivo engineering of a functional tendon sheath in a hen model.

    Science.gov (United States)

    Xu, Liang; Cao, Dejun; Liu, Wei; Zhou, Guangdong; Zhang, Wen Jie; Cao, Yilin

    2010-05-01

    Repair of injured tendon sheath remains a major challenge and this study explored the possibility of in vivo reconstruction of a tendon sheath with tendon sheath derived cells and polyglycolic acid (PGA) fibers in a Leghorn hen model. Total 55 Leghorn hens with a 1cm tendon sheath defect created in the left middle toe of each animal were randomly assigned into: (1) experimental group (n=19) that received a cell-PGA construct; (2) scaffold control group (n=18) that received a cell-free PGA scaffold; (3) blank control group (n=18) with the defect untreated. Tendon sheath cells were isolated, in vitro expanded, and seeded onto PGA scaffolds. After in vitro culture for 7 days, the constructs were in vivo implanted to repair the sheath defects. Alcian blue staining confirmed the ability of cultured cells to produce specific matrices containing acidic carboxyl mucopolysaccharide (mainly hyaluronic acid). In addition, the engineered sheath formed a relatively mature structure at 12 weeks post-surgery, which was similar to that of native counterpart, including a smooth inner surface, a well-developed sheath histological structure with a clear space between the tendon and the engineered sheath. More importantly, Work of Flexion assay revealed that the tendons needed less power consumption to glide inside the engineered sheath when compared to the tendons which were surrounded by scar-repaired tissues, indicating that the engineered sheaths had gained the function to a certain extent of preventing tendon adhesion. Taken together, these results suggest that tendon sheaths that are functionally and structurally similar to native sheaths are possible to be engineered in vivo using tendon sheath cells and PGA scaffolds. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Regional strain variations in the human patellar tendon.

    Science.gov (United States)

    Pearson, Stephen J; Ritchings, Tim; Mohamed, Azlan S A

    2014-07-01

    Characteristics of localized tendon strain in vivo are largely unknown. The present study examines local tendon strain between the deep, middle, and surface structures at the proximal and distal aspects of the patellar tendon during ramped isometric contractions. Male subjects (age 28.0 ± 6.3 yr) were examined for patellar tendon excursion (anterior, midsection, and posterior) during ramped isometric voluntary contractions using real-time B-mode ultrasonography and dynamometry. Regional tendon excursion measurements were compared using an automated pixel tracking method. Strain was determined from the tendon delta length normalized to initial/resting segment length. Strain increased from 10% to 100% of force for all regions. Significantly greater mean strain was seen for the anterior proximal region compared to the posterior and mid layer of the tendon (7.5% ± 1.1% vs 3.7% ± 0.5% vs 5.5% ± 1.0%; P < 0.05). Similarly, the distal posterior region showed greater mean strain compared to the mid and anterior regions (7.9% ± 0.6% vs 5.0% ± 0.6% vs 5.4% ± 0.6%; P < 0.05). Relative changes in strain differences from 50% to 100% of force for the proximal region were greatest for the anterior to midline regions (4.6% ± 0.6% and 5.6% ± 0.6%, respectively) and those for the distal region were also greatest for the anterior to midline regions (4.4% ± 0.2% and 5.3% ± 0.2%, respectively). The largest mean strain for the proximal region was at the anterior layer (7.5% ± 1.1%) and that for the distal tendon region was at the posterior layer (7.9% ± 0.9%). This study shows significant regional differences in strain during ramped isometric contractions for the patellar tendon. Lower proximal strains in the posterior tendon compared to the anterior region may be associated with the suggestion of "stress shielding" as an etiological factor in insertional tendinopathy.

  5. Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

    OpenAIRE

    Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Gaida, Jamie; Docking, Sean; Purdam, Craig; Cook, Jill

    2015-01-01

    Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, curre...

  6. Presence of Bacteria in Spontaneous Achilles Tendon Ruptures.

    Science.gov (United States)

    Rolf, Christer G; Fu, Sai-Chuen; Hopkins, Chelsea; Luan, Ju; Ip, Margaret; Yung, Shu-Hang; Friman, Göran; Qin, Ling; Chan, Kai-Ming

    2017-07-01

    The structural pathology of Achilles tendon (AT) ruptures resembles tendinopathy, but the causes remain unknown. Recently, a number of diseases were found to be attributed to bacterial infections, resulting in low-grade inflammation and progressive matrix disturbance. The authors speculate that spontaneous AT ruptures may also be influenced by the presence of bacteria. Bacteria are present in ruptured ATs but not in healthy tendons. Cross-sectional study; Level of evidence, 3. Patients with spontaneous AT ruptures and patients undergoing anterior cruciate ligament (ACL) reconstruction were recruited for this study. During AT surgical repair, excised tendinopathic tissue was collected, and healthy tendon samples were obtained as controls from hamstring tendon grafts used in ACL reconstruction. Half of every sample was reserved for DNA extraction and the other half for histology. Polymerase chain reaction (PCR) was conducted using 16S rRNA gene universal primers, and the PCR products were sequenced for the identification of bacterial species. A histological examination was performed to compare tendinopathic changes in the case and control samples. Five of 20 AT rupture samples were positive for the presence of bacterial DNA, while none of the 23 hamstring tendon samples were positive. Sterile operating and experimental conditions and tests on samples, controlling for harvesting and processing procedures, ruled out the chance of postoperative bacterial contamination. The species identified predominantly belonged to the Staphylococcus genus. AT rupture samples exhibited histopathological features characteristic of tendinopathy, and most healthy hamstring tendon samples displayed normal tendon features. There were no apparent differences in histopathology between the bacterial DNA-positive and bacterial DNA-negative AT rupture samples. The authors have demonstrated the presence of bacterial DNA in ruptured AT samples. It may suggest the potential involvement of bacteria

  7. Achilles tendon and sports; Die Achillessehne im Sport

    Energy Technology Data Exchange (ETDEWEB)

    Ulreich, N.; Kainberger, F. [Univ.-Klinik fuer Radiodiagnostik Wien (Austria); Huber, W.; Nehrer, S. [Univ.-Klinik fuer Orthopaedie Wien (Austria)

    2002-10-01

    Because of the rising popularity of recreational sports activities achillodynia is an often associated symptom with running, soccer and athletics. Therefore radiologist are frequently asked to image this tendon. The origin of the damage of the Achilles tendon is explained by numerous hypothesis, mainly a decreased perfusion and a mechanical irritation that lead to degeneration of the tendon. High-resolution technics such as sonography and magnetic resonance imaging show alterations in the structure of the tendon which can be graduated and classified. Manifestations like tendinosis, achillobursitis, rupture and Haglunds disease can summarized as the tendon overuse syndrom. A rupture of a tendon is mostly the result of a degeneration of the collagenfibres. The task of the radiologist is to acquire the intrinsic factors for a potential rupture. (orig.) [German] Aufgrund des starken Anstiegs des Freizeitsportes sind Achillodynien ein besonders mit Laufsport, Fussball und Leichtathletik assoziiertes Symptom und die Indikation zur radiologischen Abklaerung wird oft gestellt. Die Entstehung von Sehnenschaeden wird durch eine Reihe von Hypothesen erklaert, wobei eine gestoerte Gewebeperfusion und eine mechanische Irritation als Hauptursachen angesehen werden, die zur Degeneration des Sehnengewebes und des umgebenden Gleitlagers fuehren. Sie koennen aufgrund sonographischer und MR-tomographischer Zeichen meist klar klassifiziert und graduiert werden, wobei hochaufloesende Techniken eine wesentliche Voraussetzung fuer die subtile Analyse der Sehnenstruktur darstellen. Die einzelnen klinischen Erscheinungsformen wie Tendinose, Achillobursitis, Haglund-Ferse und Sehnenruptur koennen unter dem Begriff des ''Sehnenueberlastungssyndroms'' (Tendon overuse syndrome) subsummiert werden. Rupturen der Achillessehne treten so gut wie immer bei bereits vorgeschaedigtem Kollagenfasergewebe auf, und der radiologischen Diagnostik kommt wesentliche Bedeutung dabei zu

  8. MRI of tibialis anterior tendon rupture

    International Nuclear Information System (INIS)

    Gallo, Robert A.; DeMeo, Patrick J.; Kolman, Brett H.; Daffner, Richard H.; Sciulli, Robert L.; Roberts, Catherine C.

    2004-01-01

    Ruptures of the tibialis anterior tendon are rare. We present the clinical histories and MRI findings of three recent male patients with tibialis anterior tendon rupture aged 58-67 years, all of whom presented with pain over the dorsum of the ankle. Two of the three patients presented with complete rupture showing discontinuity of the tendon, thickening of the retracted portion of the tendon, and excess fluid in the tendon sheath. One patient demonstrated a partial tear showing an attenuated tendon with increased surrounding fluid. Although rupture of the tibialis anterior tendon is a rarely reported entity, MRI is a useful modality in the definitive detection and characterization of tibialis anterior tendon ruptures. (orig.)

  9. Anti-inflammatory management for tendon injuries - friends or foes?

    Directory of Open Access Journals (Sweden)

    Chan Kai-Ming

    2009-10-01

    Full Text Available Abstract Acute and chronic tendon injuries are very common among athletes and in sedentary population. Most physicians prescribe anti-inflammatory managements to relieve the worst symptoms of swelling and pain, including non-steroidal anti-inflammatory drugs, corticosteroids and physical therapies. However, experimental research shows that pro-inflammatory mediators such as prostaglandins may play important regulatory roles in tendon healing. Noticeably nearly all cases of chronic tendon injuries we treat as specialists have received non-steroidal anti-inflammatory drugs by their physician, suggesting that there might be a potential interaction in some of these cases turning a mild inflammatory tendon injury into chronic tendinopathy in predisposed individuals. We are aware of the fact that non-steroidal anti-inflammatory drugs and corticosteroids may well have a positive effect on the pain control in the clinical situation whilst negatively affect the structural healing. It follows that a comprehensive evaluation of anti-inflammatory management for tendon injuries is needed and any such data would have profound clinical and health economic importance.

  10. Faster Movement Speed Results in Greater Tendon Strain during the Loaded Squat Exercise

    Science.gov (United States)

    Earp, Jacob E.; Newton, Robert U.; Cormie, Prue; Blazevich, Anthony J.

    2016-01-01

    Introduction: Tendon dynamics influence movement performance and provide the stimulus for long-term tendon adaptation. As tendon strain increases with load magnitude and decreases with loading rate, changes in movement speed during exercise should influence tendon strain. Methods: Ten resistance-trained men [squat one repetition maximum (1RM) to body mass ratio: 1.65 ± 0.12] performed parallel-depth back squat lifts with 60% of 1RM load at three different speeds: slow fixed-tempo (TS: 2-s eccentric, 1-s pause, 2-s concentric), volitional-speed without a pause (VS) and maximum-speed jump (JS). In each condition joint kinetics, quadriceps tendon length (LT), patellar tendon force (FT), and rate of force development (RFDT) were estimated using integrated ultrasonography, motion-capture, and force platform recordings. Results: Peak LT, FT, and RFDT were greater in JS than TS (p < 0.05), however no differences were observed between VS and TS. Thus, moving at faster speeds resulted in both greater tendon stress and strain despite an increased RFDT, as would be predicted of an elastic, but not a viscous, structure. Temporal comparisons showed that LT was greater in TS than JS during the early eccentric phase (10–14% movement duration) where peak RFDT occurred, demonstrating that the tendon's viscous properties predominated during initial eccentric loading. However, during the concentric phase (61–70 and 76–83% movement duration) differing FT and similar RFDT between conditions allowed for the tendon's elastic properties to predominate such that peak tendon strain was greater in JS than TS. Conclusions: Based on our current understanding, there may be an additional mechanical stimulus for tendon adaptation when performing large range-of-motion isoinertial exercises at faster movement speeds. PMID:27630574

  11. Achilles Tendon's Tear

    OpenAIRE

    F. Shahandeh

    2008-01-01

    Introduction: The achilles and plantaris tendons to-gether makeup the posterior grouptendons of ankle. Their seldom confusion in interpreting MR images of the achilles tendon. The achilles tendon should ap-pear informally straight and black on sagital T1 weighted images and on fluid sensitive images."nCase Presentation: After a heavy sport, a 55 year-old woman cannot walk with right foot."nDiscussion: The classic achilles tendon rupture occurs with forced dorsiflexion of planted foo...

  12. Pathophysiology of overuse tendon injury

    International Nuclear Information System (INIS)

    Kannus, P.; Paavola, M.; Paakkala, T.; Parkkari, J.; Jaervinen, T.; Jaervinen, M.

    2002-01-01

    Overuse tendon injury is one of the most common injuries in sports.The etiology as well as the pathophysilogical mechanisms leading to tendinopathy are of crucial medical importance.At the moment intrinsic and extrinsic factors are assumed as mechanisms of overuse tendon injury. Except for the acute, extrinsic trauma, the chronic overuse tendon injury is a multifactorial process. There are many other factors, such as local hypoxia, less of nutrition, impaired metabolism and local inflammatory that may also contribute to the development of tissue damage.The exact interaction of these factors cannot be explained entirely at the moment.Further studies will be necessary in order to get more information. (orig.) [de

  13. Osteocalcin expressing cells from tendon sheaths in mice contribute to tendon repair by activating Hedgehog signaling

    OpenAIRE

    Wang, Yi; Zhang, Xu; Huang, Huihui; Xia, Yin; Yao, YiFei; Mak, Arthur Fuk-Tat; Yung, Patrick Shu-Hang; Chan, Kai-Ming; Wang, Li; Zhang, Chenglin; Huang, Yu; Mak, Kingston King-Lun

    2017-01-01

    Both extrinsic and intrinsic tissues contribute to tendon repair, but the origin and molecular functions of extrinsic tissues in tendon repair are not fully understood. Here we show that tendon sheath cells harbor stem/progenitor cell properties and contribute to tendon repair by activating Hedgehog signaling. We found that Osteocalcin (Bglap) can be used as an adult tendon-sheath-specific marker in mice. Lineage tracing experiments show that Bglap-expressing cells in adult sheath tissues pos...

  14. Mechanical anchorage of FRP tendons – A literature review

    DEFF Research Database (Denmark)

    Schmidt, Jacob W.; Bennitz, Anders; Täljsten, Björn

    2012-01-01

    High tensile strength, good resistance to degradation and creep, low weight and, to some extent, the ability to change the modulus of elasticity are some of the advantages of using prestressed, unidirectional FRP (Fibre Reinforced Polymer) tendon systems. Bonded and non-bonded versions of these s......High tensile strength, good resistance to degradation and creep, low weight and, to some extent, the ability to change the modulus of elasticity are some of the advantages of using prestressed, unidirectional FRP (Fibre Reinforced Polymer) tendon systems. Bonded and non-bonded versions...... with such systems. This is especially important in external post-tensioned tendon systems, where the anchorage points are exposed to the full load throughout the life span of the structure. Consequently, there are large requirements related to the long-term capacity and fatigue resistance of such systems. Several...

  15. Morpho-functional changes in human tendon tissue

    Directory of Open Access Journals (Sweden)

    I Galliani

    2009-12-01

    Full Text Available Insertion tissue biopsies of right arm common extensor tendons from 11 patients with chronic lateral epicondylitis were processed for light and electron microscopy. The subjects were aged between 38 and 54 years (only one was 25. The specimens showed a variety of structural changes such as biochemical and spatial alteration of collagen, hyaline degeneration, loss of tenocytes, fibrocartilage metaplasia, calcifying processes, neovascularization and vessel wall modifications. Tissue alterations were evident in limited zones of the tendon fibrocartilage in which the surgical resection was generally visible. The areas where the degenerative processes were localized, were restricted and in spatial contiguity with morphologically normal ones. The observed cases presented histological and electron microscopic findings that characterize lateral epicondylitis as a degenerative phenomenon involving all tendon components.

  16. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  17. A practical approach to magnetic resonance imaging of normal and injured tendons: pictorial essay

    International Nuclear Information System (INIS)

    Forster, B.B.; Khan, K.M.

    2003-01-01

    The imaging of tendon injury can be troublesome from a number of perspectives. First, tendon injuries are extremely common, accounting for 30%-50% of all sports injuries, and are, therefore, seen frequently at imaging centers. Second, tendons have a unique histology and ultra-structure with a number of normal variations that can mimic pathologic conditions, of which the radiologist should be aware. Finally, although full-thickness tears are easily diagnosed both clinically and with imaging, imaging findings for partial tears overlap those of tendinosis and those of normal tendons, and this can be very troublesome for radiologists, clinicians and patients alike. The objective of this article is to develop a practical approach to the magnetic resonance imaging (MRI) and analysis of tendons, both normal and pathologic, emphasizing the common features at different anatomic locations. (author)

  18. A practical approach to magnetic resonance imaging of normal and injured tendons: pictorial essay

    Energy Technology Data Exchange (ETDEWEB)

    Forster, B.B. [UBC Hospital, Dept. of Radiology, Vancouver, British Columbia (Canada); Khan, K.M. [Univ. of British Columbia, Dept. of Family Practice, Vancouver, British Columbia (Canada)

    2003-10-01

    The imaging of tendon injury can be troublesome from a number of perspectives. First, tendon injuries are extremely common, accounting for 30%-50% of all sports injuries, and are, therefore, seen frequently at imaging centers. Second, tendons have a unique histology and ultra-structure with a number of normal variations that can mimic pathologic conditions, of which the radiologist should be aware. Finally, although full-thickness tears are easily diagnosed both clinically and with imaging, imaging findings for partial tears overlap those of tendinosis and those of normal tendons, and this can be very troublesome for radiologists, clinicians and patients alike. The objective of this article is to develop a practical approach to the magnetic resonance imaging (MRI) and analysis of tendons, both normal and pathologic, emphasizing the common features at different anatomic locations. (author)

  19. Improved Achilles tendon healing by early mechanical loading in a rabbit model.

    Science.gov (United States)

    Wang, Jihong; Jiang, Dianming; Wen, Shuzheng; Jing, Shangfei; Fan, Dongsheng; Hao, Zengtao; Han, Chaoqian

    2015-01-01

    To investigate the structure and the attachment strength of a healing tendon-bone interface and the role of mechanical loading in tendon healing. Sixty rabbits underwent unilateral detachment and repair of the Achilles tendon. Thirty animals were immobilized (Group A), and the others wereallowed loadingimmediately postoperatively (Group B). Animals were sacrificed at 4 weeks and evaluated for histological and biomechanical testing. Statistical analysis was performed with an independent t test with significance set at P = 0.05. The ultimate stress was greater in group B (4.598 ± 1.321 N/mm(2)) compared with the control group (3.388 ± 0.994 N/mm(2)) (P tendon-to-bone interface with a larger area of chondrocytes was found in group B (P tendon-to-bone interface.

  20. Magnetic resonance imaging of the elbow. Part II: Abnormalities of the ligaments, tendons, and nerves

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Tuite, Michael; Sanford, Matthew [University of Wisconsin Hospital, Department of Radiology, Madison, WI (United States)

    2005-01-01

    Part II of this comprehensive review on magnetic resonance imaging of the elbow discusses the role of magnetic resonance imaging in evaluating patients with abnormalities of the ligaments, tendons, and nerves of the elbow. Magnetic resonance imaging can yield high-quality multiplanar images which are useful in evaluating the soft tissue structures of the elbow. Magnetic resonance imaging can detect tears of the ulnar collateral ligament and lateral collateral ligament of the elbow with high sensitivity and specificity. Magnetic resonance imaging can determine the extent of tendon pathology in patients with medial epicondylitis and lateral epicondylitis. Magnetic resonance imaging can detect tears of the biceps tendon and triceps tendon and can distinguishing between partial and complete tendon rupture. Magnetic resonance imaging is also helpful in evaluating patients with nerve disorders at the elbow. (orig.)

  1. Adipose derived stromal vascular fraction improves early tendon healing: an experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Mehdi Behfar

    2011-11-01

    Full Text Available Tendon never restores the complete biological and mechanical properties after healing. Bone marrow and recently adipose tissue have been used as the sources of mesenchymal stem cells, which have been proven to enhance tendon healing. Stromal vascular fraction (SVF, derived from adipose tissue by an enzymatic digestion, represents an alternative source of multipotent cells, which undergo differentiation into multiple lineages to be used in regenerative medicine. In the present study, we investigated potentials of this source on tendon healing. Twenty rabbits were divided into control and treatment groups. Five rabbits were used as donors of adipose tissue. The injury model was unilateral complete transection through the middle one third of deep digital flexor tendon. Immediately after suture repair, either fresh stromal vascular fraction from enzymatic digestion of adipose tissue or placebo was intratendinously injected into the suture site in treatments and controls, respectively. Cast immobilization was continued for two weeks after surgery. Animals were sacrificed at the third week and tendons underwent histological, immunohistochemical, and mechanical evaluations. By histology, improved fibrillar organization and remodeling of neotendon were observed in treatment group. Immunohistochemistry revealed an insignificant increase in collagen type III and I expression in treatments over controls. Mechanical testing showed significant increase in maximum load and energy absorption in SVF treated tendons. The present study showed that intratendinous injection of uncultured adipose derived stromal vascular fraction improved structural and mechanical properties of repaired tendon and it could be an effective modality for treating tendon laceration.

  2. Local administration of insulin-like growth factor-I (IGF-I) stimulates tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Hansen, Mette; Boesen, Anders; Holm, Lars

    2013-01-01

    Collagen is the predominant structural protein in tendons and ligaments, and can be controlled by hormonal changes. In animals, injections of insulin-like growth factor I (IGF-I) has been shown to increase collagen synthesis in tendons and ligaments and to improve structural tissue healing, but t...

  3. Can PRP effectively treat injured tendons?

    Science.gov (United States)

    Wang, James H-C

    2014-01-01

    PRP is widely used to treat tendon and other tissue injuries in orthopaedics and sports medicine; however, the efficacy of PRP treatment on injured tendons is highly controversial. In this commentary, I reason that there are many PRP- and patient-related factors that influence the outcomes of PRP treatment on injured tendons. Therefore, more basic science studies are needed to understand the mechanism of PRP on injured tendons. Finally, I suggest that better understanding of the PRP action mechanism will lead to better use of PRP for the effective treatment of tendon injuries in clinics.

  4. Bioreactor design for tendon/ligament engineering.

    Science.gov (United States)

    Wang, Tao; Gardiner, Bruce S; Lin, Zhen; Rubenson, Jonas; Kirk, Thomas B; Wang, Allan; Xu, Jiake; Smith, David W; Lloyd, David G; Zheng, Ming H

    2013-04-01

    Tendon and ligament injury is a worldwide health problem, but the treatment options remain limited. Tendon and ligament engineering might provide an alternative tissue source for the surgical replacement of injured tendon. A bioreactor provides a controllable environment enabling the systematic study of specific biological, biochemical, and biomechanical requirements to design and manufacture engineered tendon/ligament tissue. Furthermore, the tendon/ligament bioreactor system can provide a suitable culture environment, which mimics the dynamics of the in vivo environment for tendon/ligament maturation. For clinical settings, bioreactors also have the advantages of less-contamination risk, high reproducibility of cell propagation by minimizing manual operation, and a consistent end product. In this review, we identify the key components, design preferences, and criteria that are required for the development of an ideal bioreactor for engineering tendons and ligaments.

  5. Tendoscopy of the peroneal tendons

    NARCIS (Netherlands)

    van Dijk, C. N.; Kort, N.

    1998-01-01

    An anatomic cadaver study was performed. Subsequently, in a prospective study, diagnostic and therapeutic tendoscopy (tendon sheath endoscopy) was performed in nine consecutive patients with a history of persistent posterolateral ankle pain for at least 6 months. All patients had pain on palpation

  6. Smart Tendon Actuated Flexible Actuator

    Directory of Open Access Journals (Sweden)

    Md. Masum Billah

    2015-01-01

    Full Text Available We investigate the kinematic feasibility of a tendon-based flexible parallel platform actuator. Much of the research on tendon-driven Stewart platforms is devoted either to the completely restrained positioning mechanism (CRPM or to one particular type of the incompletely restrained positioning mechanism (IRPM where the external force is provided by the gravitational pull on the platform such as in cable-suspended Stewart platforms. An IRPM-based platform is proposed which uses the external force provided by a compliant member. The compliant central column allows the configuration to achieve n DOFs with n tendons. In particular, this investigation focuses on the angular deflection of the upper platform with respect to the lower platform. The application here is aimed at developing a linkable module that can be connected to one another so as to form a “snake robot” of sorts. Since locomotion takes precedence over positioning in this application, a 3-DOF Stewart platform is adopted. For an arbitrary angular displace of the end-effector, the corresponding length of each tendon can be determined through inverse kinematics. Mathematical singularities are investigated using the traditional analytical method of defining the Jacobian.

  7. Increased mast cell numbers in a calcaneal tendon overuse model.

    Science.gov (United States)

    Pingel, J; Wienecke, J; Kongsgaard, M; Behzad, H; Abraham, T; Langberg, H; Scott, A

    2013-12-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats were divided in two groups: running group (n = 12); sedentary control group (n = 12). The running-group was exposed to the HIUR exercise protocol for 7 weeks. The calcaneal tendons of both hind limbs were dissected. The right tendon was used for histologic analysis using Bonar score, immunohistochemistry, and second harmonic generation microscopy (SHGM). The left tendon was used for quantitative polymerase chain reaction (qPCR) analysis. An increased tendon cell density in the runners were observed compared to the controls (P = 0.05). Further, the intensity of immunostaining of protein kinase B, P = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further that these changes are associated with an increased mast cell density. © 2013 The Authors. Scand J Med Sci Sports published by John Wiley & Sons Ltd.

  8. Hyperuricemic PRP in Tendon Cells

    Directory of Open Access Journals (Sweden)

    I. Andia

    2014-01-01

    Full Text Available Platelet-rich plasma (PRP is injected within tendons to stimulate healing. Metabolic alterations such as the metabolic syndrome, diabetes, or hyperuricemia could hinder the therapeutic effect of PRP. We hypothesise that tendon cells sense high levels of uric acid and this could modify their response to PRP. Tendon cells were treated with allogeneic PRPs for 96 hours. Hyperuricemic PRP did not hinder the proliferative actions of PRP. The gene expression pattern of inflammatory molecules in response to PRP showed absence of IL-1b and COX1 and modest expression of IL6, IL8, COX2, and TGF-b1. IL8 and IL6 proteins were secreted by tendon cells treated with PRP. The synthesis of IL6 and IL8 proteins induced by PRP is decreased significantly in the presence of hyperuricemia (P = 0.017 and P = 0.012, resp.. Concerning extracellular matrix, PRP-treated tendon cells displayed high type-1 collagen, moderate type-3 collagen, decorin, and hyaluronan synthase-2 expression and modest expression of scleraxis. Hyperuricemia modified the expression pattern of extracellular matrix proteins, upregulating COL1 (P = 0.036 and COMP (P = 0.012 and downregulating HAS2 (P = 0.012. Positive correlations between TGF-b1 and type-1 collagen (R = 0.905, P = 0.002 and aggrecan (R = 0.833, P = 0.010 and negative correlations between TGF-b1 and IL6 synthesis (R = −0.857, P = 0.007 and COX2 (R = −0.810, P = 0.015 were found.

  9. Ultrasound elasticity imaging of human posterior tibial tendon

    Science.gov (United States)

    Gao, Liang

    Posterior tibial tendon dysfunction (PTTD) is a common degenerative condition leading to a severe impairment of gait. There is currently no effective method to determine whether a patient with advanced PTTD would benefit from several months of bracing and physical therapy or ultimately require surgery. Tendon degeneration is closely associated with irreversible degradation of its collagen structure, leading to changes to its mechanical properties. If these properties could be monitored in vivo, it could be used to quantify the severity of tendonosis and help determine the appropriate treatment. Ultrasound elasticity imaging (UEI) is a real-time, noninvasive technique to objectively measure mechanical properties in soft tissue. It consists of acquiring a sequence of ultrasound frames and applying speckle tracking to estimate displacement and strain at each pixel. The goals of my dissertation were to 1) use acoustic simulations to investigate the performance of UEI during tendon deformation with different geometries; 2) develop and validate UEI as a potentially noninvasive technique for quantifying tendon mechanical properties in human cadaver experiments; 3) design a platform for UEI to measure mechanical properties of the PTT in vivo and determine whether there are detectable and quantifiable differences between healthy and diseased tendons. First, ultrasound simulations of tendon deformation were performed using an acoustic modeling program. The effects of different tendon geometries (cylinder and curved cylinder) on the performance of UEI were investigated. Modeling results indicated that UEI accurately estimated the strain in the cylinder geometry, but underestimated in the curved cylinder. The simulation also predicted that the out-of-the-plane motion of the PTT would cause a non-uniform strain pattern within incompressible homogeneous isotropic material. However, to average within a small region of interest determined by principal component analysis (PCA

  10. Effect of Achilles tendon loading on plantar fascia tension in the standing foot.

    Science.gov (United States)

    Cheung, Jason Tak-Man; Zhang, Ming; An, Kai-Nan

    2006-02-01

    The plantar fascia, which is one of the major arch-supporting structures of the human foot, sustains high tensions during weight-bearing. A positive correlation between Achilles tendon loading and plantar fascia tension has been reported. Excessive stretching and tightness of the Achilles tendon are thought to be the risk factors of plantar fasciitis but their biomechanical effects on the plantar fascia have not been fully addressed. A three-dimensional finite element model of the human foot and ankle, incorporating geometrical and material nonlinearity, was employed to investigate the loading response of the plantar fascia in the standing foot with different magnitudes of Achilles tendon loading. With the total ground reaction forces of one foot maintained at 350 N to represent half body weight, an increase in Achilles tendon load from (0-700 N) resulted in a general increase in total force and peak plantar pressure at the forefoot of up to about 250%. There was a lateral and anterior shift of the centre of pressure and a reduction in the arch height with an increasing Achilles tendon load as a result of the plantar flexion moment on the calcaneus. From the finite element predictions of simulated balanced standing, Achilles tendon forces of 75% of the total weight on the foot (350 N) were found to provide the closest match of the measured centre of pressure of the subject during balanced standing. Both the weight on the foot and Achilles tendon loading resulted in an increase in tension of the plantar fascia with the latter showing a two-times larger straining effect. Increasing tension on the Achilles tendon is coupled with an increasing strain on the plantar fascia. Overstretching of the Achilles tendon resulting from intense muscle contraction and passive stretching of tight Achilles tendon are plausible mechanical factors for overstraining of the plantar fascia.

  11. Tissue-Engineered Tendon for Enthesis Regeneration in a Rat Rotator Cuff Model

    Directory of Open Access Journals (Sweden)

    Michael J. Smietana

    2017-06-01

    Full Text Available Healing of rotator cuff (RC injuries with current suture or augmented scaffold techniques fails to regenerate the enthesis and instead forms a weaker fibrovascular scar that is prone to subsequent failure. Regeneration of the enthesis is the key to improving clinical outcomes for RC injuries. We hypothesized that the utilization of our tissue-engineered tendon to repair either an acute or a chronic full-thickness supraspinatus tear would regenerate a functional enthesis and return the biomechanics of the tendon back to that found in native tissue. Engineered tendons were fabricated from bone marrow-derived mesenchymal stem cells utilizing our well-described fabrication technology. Forty-three rats underwent unilateral detachment of the supraspinatus tendon followed by acute (immediate or chronic (4 weeks retracted repair by using either our engineered tendon or a trans-osseous suture technique. Animals were sacrificed at 8 weeks. Biomechanical and histological analyses of the regenerated enthesis and tendon were performed. Statistical analysis was performed by using a one-way analysis of variance with significance set at p < 0.05. Acute repairs using engineered tendon had improved enthesis structure and lower biomechanical failures compared with suture repairs. Chronic repairs with engineered tendon had a more native-like enthesis with increased fibrocartilage formation, reduced scar formation, and lower biomechanical failure compared with suture repair. Thus, the utilization of our tissue-engineered tendon showed improve enthesis regeneration and improved function in chronic RC repairs compared with suture repair. Clinical Significance: Our engineered tendon construct shows promise as a clinically relevant method for repair of RC injuries.

  12. Test of measuring frictional loss of tendons for PCCVs and others

    International Nuclear Information System (INIS)

    Igaki, Tsutomu; Kondo, Shigeru; Tadano, Naonori.

    1981-01-01

    Kansai Electric Power Co., Inc., has carried out the experimental research on large capacity tendons in order to introduce the prestressing structurally required for PCCVs since 1978. This experimental research is concerned with large circular cylinder structures using the large capacity tendons of unbonded type, and aimed at clarifying the problems concerning their design and construction. Through the experiment of prestressing the partial models of full size with the tendons of 1000 t class, the basic experiment on materials, the investigations of concrete placing and tendon arrangement, and the measurement before and after prestressing were carried out, and the studies on the loss of tension the soundness of anchoring part, and the capability of construction were made. The specimens were a rectangular block with 14 tendons, a circular cylinder of two-buttress type with 3 tendons, a U-type specimen simulating the vertical section and a C-type specimen simulating the horizontal section. It seems advantageous to decrease the number of buttresses in view of workability and economy when large capacity tendons are used, and it was confirmed that two-buttress construction did not cause problem at all. It was judged that the anchoring part was sufficiently safe. Concerning the friction during tensioning, the effectiveness rate was estimated. (Kako, I.)

  13. In-vitro tensile testing machine for vibration study of fresh rabbit Achilles tendon

    Science.gov (United States)

    Revel, Gian M.; Scalise, Alessandro; Scalise, Lorenzo; Pianosi, Antonella

    2001-10-01

    A lot of people, overall athletic one suffer from tendinitis or complete rupture of the Achilles tendon. This structure becomes inflamed and damaged mainly from a variety of mechanical forces and sometimes due to metabolic problems, such as diabetes or arthritis. Over the past three decades extensive studies have been performed on the structural and mechanical properties of Achilles tendon trying to explain the constitutive equations to describe and foresee tendon behavior. Among the various mechanical parameters, the vibrational behavior is also of interest. Several investigations are performed in order to study how the Achilles tendon vibrations influence the response of the muscle proprioception and human posture. The present article describes how in vitro tensile experiments can be performed, taking into account the need to simulate physiological condition of Achilles tendon and thus approaching some opened problems in the design of the experimental set-up. A new system for evaluating tendon vibrations by non contact techniques is proposed. Preliminary simple elongation tests are made extracting the main mechanical parameters: stress and strain at different fixed stretches, in order to characterize the tissue. Finally, a vibration study is made at each pretensioned tendon level evaluating the oscillating curves caused by a small hammer.

  14. Magnetotherapy: The quest for tendon regeneration.

    Science.gov (United States)

    Pesqueira, Tamagno; Costa-Almeida, Raquel; Gomes, Manuela E

    2018-05-09

    Tendons are mechanosensitive tissues that connect and transmit the forces generated by muscles to bones by allowing the conversion of mechanical input into biochemical signals. These physical forces perform the fundamental work of preserving tendon homeostasis assuring body movements. However, overloading causes tissue injuries, which leads us to the field of tendon regeneration. Recently published reviews have broadly shown the use of biomaterials and different strategies to attain tendon regeneration. In this review, our focus is the use of magnetic fields as an alternative therapy, which has demonstrated clinical relevance in tendon medicine because of their ability to modulate cell fate. Yet the underlying cellular and molecular mechanisms still need to be elucidated. While providing a brief outlook about specific signalling pathways and intracellular messengers as framework in play by tendon cells, application of magnetic fields as a subcategory of physical forces is explored, opening up a compelling avenue to enhance tendon regeneration. We outline here useful insights on the effects of magnetic fields both at in vitro and in vivo levels, particularly on the expression of tendon genes and inflammatory cytokines, ultimately involved in tendon regeneration. Subsequently, the potential of using magnetically responsive biomaterials in tendon tissue engineering is highlighted and future directions in magnetotherapy are discussed. © 2018 Wiley Periodicals, Inc.

  15. Ipsilateral free semitendinosus tendon graft transfer for reconstruction of chronic tears of the Achilles tendon

    Directory of Open Access Journals (Sweden)

    Gougoulias Nikolaos

    2008-07-01

    Full Text Available Abstract Background Many techniques have been developed for the reconstruction of the Achilles tendon in chronic tears. In presence of a large gap (greater than 6 centimetres, tendon augmentation is required. Methods We present our method of minimally invasive semitendinosus reconstruction for the Achilles tendon using one para-midline and one midline incision. Results The first incision is a 5 cm longitudinal incision, made 2 cm proximal and just medial to the palpable end of the residual tendon. The second incision is 3 cm long and is also longitudinal but is 2 cm distal and in the midline to the distal end of the tendon rupture. The distal and proximal Achilles tendon stumps are mobilised. After trying to reduce the gap of the ruptured Achilles tendon, if the gap produced is greater than 6 cm despite maximal plantar flexion of the ankle and traction on the Achilles tendon stumps, the ipsilateral semitendinosus tendon is harvested. The semitendinosus tendon is passed through small incisions in the substance of the proximal stump of the Achilles tendon, and it is sutured to the Achilles tendon. It is then passed beneath the intact skin bridge into the distal incision, and passed from medial to lateral through a transverse tenotomy in the distal stump. With the ankle in maximal plantar flexion, the semitendinosus tendon is sutured to the Achilles tendon at each entry and exit point Conclusion This minimally invasive technique allows reconstruction of the Achilles tendon using the tendon of semitendinosus preserving skin integrity over the site most prone to wound breakdown, and can be especially used to reconstruct the Achilles tendon in the presence of large gap (greater than 6 centimetres.

  16. Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration.

    Science.gov (United States)

    Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

    2012-12-15

    Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7-21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy.

  17. Active Achilles tendon kinesitherapy accelerates Achilles tendon repair by promoting neurite regeneration☆

    Science.gov (United States)

    Jielile, Jiasharete; Aibai, Minawa; Sabirhazi, Gulnur; Shawutali, Nuerai; Tangkejie, Wulanbai; Badelhan, Aynaz; Nuerduola, Yeermike; Satewalede, Turde; Buranbai, Darehan; Hunapia, Beicen; Jialihasi, Ayidaer; Bai, Jingping; Kizaibek, Murat

    2012-01-01

    Active Achilles tendon kinesitherapy facilitates the functional recovery of a ruptured Achilles tendon. However, protein expression during the healing process remains a controversial issue. New Zealand rabbits, aged 14 weeks, underwent tenotomy followed immediately by Achilles tendon microsurgery to repair the Achilles tendon rupture. The tendon was then immobilized or subjected to postoperative early motion treatment (kinesitherapy). Mass spectrography results showed that after 14 days of motion treatment, 18 protein spots were differentially expressed, among which, 12 were up-regulated, consisting of gelsolin isoform b and neurite growth-related protein collapsing response mediator protein 2. Western blot analysis showed that gelsolin isoform b was up-regulated at days 7–21 of motion treatment. These findings suggest that active Achilles tendon kinesitherapy promotes the neurite regeneration of a ruptured Achilles tendon and gelsolin isoform b can be used as a biomarker for Achilles tendon healing after kinesitherapy. PMID:25317130

  18. Post-tensioning tendon force loss detection using low power pulsed eddy current measurement

    Science.gov (United States)

    Kim, Ji-Min; Lee, Jun; Sohn, Hoon

    2018-04-01

    In the field of bridge engineering, pre-fabrication of a bridge member and its construction in site have been issued and studied, which achieves improved quality and rapid construction. For integration of those pre-fabricated segments into a structural member (i.e., a concrete slab, girder and pier), post-tensioning (PT) technique is adopted utilizing a high-strength steel tendon, and an effective investigation of the remaining PT tendon force is essential to assure an overall structural integrity. This study proposes a pulsed eddy current based tendon force loss detection system. A compact eddy current sensor is designed to be installed on the surface of an anchor holding a steel PT tendon. The intensity of the induced eddy current varies with PT tendon force alteration due to the magnetostriction effect of a ferromagnetic material. The advantages of the proposed system are as follows: (1) low power consumption, (2) rapid inspection, and (3) simple installation. Its performance was validated experimentally in a full-scale lab test of a 3.3-m long, 15.2-mm diameter mono-tendon that was tensioned using a universal testing machine. Tendon force was controlled from 20 to 180 kN with 20 kN interval, and eddy current responses were measured and analyzed at each force condition. The proposed damage index and the amount of force loss of PT tendon were monotonically related, and an excessive loss as much as 30 % of an initially-introduced tendon force was successfully predicted.

  19. Achilles tendon rupture in badminton.

    Science.gov (United States)

    Kaalund, S; Lass, P; Høgsaa, B; Nøhr, M

    1989-01-01

    The typical badminton player with an Achilles tendon rupture is 36 years old and, despite limbering up, is injured at the rear line in a sudden forward movement. He resumes work within three months and has a slight lack of dorsiflexion in the ankle as the main complication. Most patients resume badminton within one year, but some finish their sports career, mainly due to fear of a new injury. The investigation discusses predisposing factors and prophylactic measures. PMID:2605439

  20. Axisymmetric modeling of prestressing tendons in nuclear containment dome

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Se-Jin [DAEWOO E and C, Institute of Construction Technology, 60 Songjook-dong, Jangan-gu, Suwon, Kyonggi 440-210 (Korea, Republic of)]. E-mail: jsj@dwconst.co.kr; Chung, Chul-Hun [Department of Civil and Environmental Engineering, Dankook University, San 8, Hannam-dong, Youngsan-gu, Seoul 140-714 (Korea, Republic of)

    2005-12-15

    Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement the actual three-dimensional tendon stiffness and prestressing effect into the axisymmetric model. Prestressing tendons, which are arranged in two or three ways depending on a containment type, are converted into the equivalent layer to consider the stiffness contribution in meridional and hoop directions. In order to reflect the prestressing effect, the equivalent load method and the initial stress method are devised, respectively, and the corresponding loads or stresses are derived in terms of the axisymmetric model. The proposed schemes are verified through some numerical examples comparing the results of the axisymmetric models to those of the actual three-dimensional model. The examples show that the proper level of the prestressing in the hoop direction of the axisymmetric dome plays an important role in tracing the actual behavior induced by the prestressing. Finally, some correction factors are discussed that can further improve the analysis results.

  1. Tendon Adaptation to Sport-specific Loading in Adolescent Athletes.

    Science.gov (United States)

    Cassel, M; Carlsohn, A; Fröhlich, K; John, M; Riegels, N; Mayer, F

    2016-02-01

    Tendon adaptation due to mechanical loading is controversially discussed. However, data concerning the development of tendon thickness in adolescent athletes is sparse. The purpose of this study was to examine possible differences in Achilles (AT) and patellar tendon (PT) thickness in adolescent athletes while considering age, gender and sport-specific loading. In 500 adolescent competitive athletes of 16 different sports and 40 recreational controls both ATs and PTs were sonographically measured. Subjects were divided into 2 age groups (sport type categories (ball, combat, and water sports, combined disciplines, cycling, controls). In addition, 3 risk groups (low, moderate, high) were created according to the athlete's risk of developing tendinopathy. AT and PT thickness did not significantly differ between age groups (AT/PT:sports/cyclists and lowest in controls (p≤0.002). PT thickness was greatest in water sports and lowest in controls (p=0.02). High risk athletes presented slightly higher AT thickness compared to the low risk group (p=0.03). Increased AT and PT thickness in certain sport types compared to controls supports the hypothesis of structural tendon adaptation due to sport-specific loading. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Axisymmetric modeling of prestressing tendons in nuclear containment dome

    International Nuclear Information System (INIS)

    Jeon, Se-Jin; Chung, Chul-Hun

    2005-01-01

    Simple axisymmetric modeling of a nuclear containment building has been often employed in practice to estimate structural behavior for the axisymmetric loadings such as internal pressure. In this case, the prestressing tendons placed in the containment dome should be axisymmetrically approximated, since most dome tendons are not arranged in an axisymmetric manner. Some procedures are proposed that can realistically implement the actual three-dimensional tendon stiffness and prestressing effect into the axisymmetric model. Prestressing tendons, which are arranged in two or three ways depending on a containment type, are converted into the equivalent layer to consider the stiffness contribution in meridional and hoop directions. In order to reflect the prestressing effect, the equivalent load method and the initial stress method are devised, respectively, and the corresponding loads or stresses are derived in terms of the axisymmetric model. The proposed schemes are verified through some numerical examples comparing the results of the axisymmetric models to those of the actual three-dimensional model. The examples show that the proper level of the prestressing in the hoop direction of the axisymmetric dome plays an important role in tracing the actual behavior induced by the prestressing. Finally, some correction factors are discussed that can further improve the analysis results

  3. Degree of tendon degeneration and stage of rotator cuff disease.

    Science.gov (United States)

    Jo, Chris Hyunchul; Shin, Won Hyoung; Park, Ji Wan; Shin, Ji Sun; Kim, Ji Eun

    2017-07-01

    While tendon degeneration has been known to be an important cause of rotator cuff disease, few studies have objectively proven the association of tendon degeneration and rotator cuff disease. The purpose of this study was to investigate changes of tendon degeneration with respect to the stage of rotator cuff disease. A total of 48 patients were included in the study: 12 with tendinopathy, 12 with a partial-thickness tear (pRCT), 12 with a full-thickness tear (fRCT), and 12 as the control. A full-thickness supraspinatus tendon sample was harvested en bloc from the middle portion between the lateral edge and the musculotendinous junction of the tendon using a biopsy punch with a diameter of 3 mm. Harvested samples were evaluated using a semi-quantitative grading scale with 7 parameters after haematoxylin and eosin staining. There was no significant difference in age, gender, symptom duration, and Kellgren-Lawrence grade between the groups except for the global fatty degeneration index. All of the seven parameters were significantly different between the groups and could be categorized as follows: early responders (fibre structure and arrangement), gradual responder (rounding of the nuclei), after-tear responders (cellularity, vascularity, and stainability), and late responder (hyalinization). The total degeneration scores were not significantly different between the control (6.08 ± 1.16) and tendinopathy (6.67 ± 1.83) (n.s.). However, the score of pRCT group (10.42 ± 1.31) was greater than that of tendinopathy (P rotator cuff disease progresses from tendinopathy to pRCT, and then to fRCT. The degree of degeneration of tendinopathy was not different from that of normal but aged tendons, and significant tendon degeneration began from the stage of pRCT. The clinical relevance of the study is that strategies and goals of the treatment for rotator cuff disease should be specific to its stage, in order to prevent disease progression for tendinopathy and pRCT, as

  4. [Application of silk-based tissue engineering scaffold for tendon / ligament regeneration].

    Science.gov (United States)

    Hu, Yejun; Le, Huihui; Jin, Zhangchu; Chen, Xiao; Yin, Zi; Shen, Weiliang; Ouyang, Hongwei

    2016-03-01

    Tendon/ligament injury is one of the most common impairments in sports medicine. The traditional treatments of damaged tissue repair are unsatisfactory, especially for athletes, due to lack of donor and immune rejection. The strategy of tissue engineering may break through these limitations, and bring new hopes to tendon/ligament repair, even regeneration. Silk is a kind of natural biomaterials, which has good biocompatibility, wide range of mechanical properties and tunable physical structures; so it could be applied as tendon/ligament tissue engineering scaffolds. The silk-based scaffold has robust mechanical properties; combined with other biological ingredients, it could increase the surface area, promote more cell adhesion and improve the biocompatibility. The potential clinical application of silk-based scaffold has been confirmed by in vivo studies on tendon/ligament repairing, such as anterior cruciate ligament, medial collateral ligament, achilles tendon and rotator cuff. To develop novel biomechanically stable and host integrated tissue engineered tendon/ligament needs more further micro and macro studies, combined with product development and clinical application, which will give new hope to patients with tendon/ligament injury.

  5. The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

    Directory of Open Access Journals (Sweden)

    Yue Song

    Full Text Available To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation.A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses and radiofrequency ablation (power control mode protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time.Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks.When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

  6. The Effects of Irreversible Electroporation on the Achilles Tendon: An Experimental Study in a Rabbit Model.

    Science.gov (United States)

    Song, Yue; Zheng, Jingjing; Yan, Mingwei; Ding, Weidong; Xu, Kui; Fan, Qingyu; Li, Zhao

    2015-01-01

    To evaluate the potential effects of irreversible electroporation ablation on the Achilles tendon in a rabbit model and to compare the histopathological and biomechanical changes between specimens following electroporation ablation and radiofrequency ablation. A total of 140 six-month-old male New Zealand rabbits were used. The animals were randomly divided into two groups, 70 in the radiofrequency ablation group and 70 in the electroporation group. In situ ablations were applied directly to the Achilles tendons of rabbits using typical electroporation (1800 V/cm, 90 pulses) and radiofrequency ablation (power control mode) protocols. Histopathological and biomechanical evaluations were performed to examine the effects of electroporation ablation and radiofrequency ablation over time. Both electroporation and radiofrequency ablation produced complete cell ablation in the target region. Thermal damage resulted in tendon rupture 3 days post radiofrequency ablation. In contrast, electroporation-ablated Achilles tendons preserved their biomechanical properties and showed no detectable rupture at this time point. The electroporation-ablated tendons exhibited signs of recovery, including tenoblast regeneration and angiogenesis within 2 weeks, and the restoration of their integral structure was evident within 12 weeks. When applying electroporation to ablate solid tumors, major advantage could be that collateral damage to adjacent tendons or ligaments is minimized due to the unique ability of electroporation ablation to target the cell membrane. This advantage could have a significant impact on the field of tumor ablation near vital tendons or ligaments.

  7. Three dimensional microstructural network of elastin, collagen, and cells in Achilles tendons.

    Science.gov (United States)

    Pang, Xin; Wu, Jian-Ping; Allison, Garry T; Xu, Jiake; Rubenson, Jonas; Zheng, Ming-Hao; Lloyd, David G; Gardiner, Bruce; Wang, Allan; Kirk, Thomas Brett

    2017-06-01

    Similar to most biological tissues, the biomechanical, and functional characteristics of the Achilles tendon are closely related to its composition and microstructure. It is commonly reported that type I collagen is the predominant component of tendons and is mainly responsible for the tissue's function. Although elastin has been found in varying proportions in other connective tissues, previous studies report that tendons contain very small quantities of elastin. However, the morphology and the microstructural relationship among the elastic fibres, collagen, and cells in tendon tissue have not been well examined. We hypothesize the elastic fibres, as another fibrillar component in the extracellular matrix, have a unique role in mechanical function and microstructural arrangement in Achilles tendons. It has been shown that elastic fibres present a close connection with the tenocytes. The close relationship of the three components has been revealed as a distinct, integrated and complex microstructural network. Notably, a "spiral" structure within fibril bundles in Achilles tendons was observed in some samples in specialized regions. This study substantiates the hierarchical system of the spatial microstructure of tendon, including the mapping of collagen, elastin and tenocytes, with 3-dimensional confocal images. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1203-1214, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. Prestressed Containments - Prestress losses and the effects of re-tensioning tendons

    International Nuclear Information System (INIS)

    Lundqvist, P.; Edin, M.; Persson, P.; Frisk, A.

    2015-01-01

    In Sweden the design of nuclear reactor containments, the structure which encloses the reactor vessel, is that of a concrete cylinder prestressed both horizontally and vertically. The main purpose of the containment is to prevent any radioactive discharge to the environment in case of e.g. an internal accident mainly through the induced compressive forces from the prestressing system. Since the tendon forces decrease with time due to long-term mechanism in the materials the remaining tendon forces are measured at regular intervals. In this paper the results from these measurements in the Swedish nuclear power plant Forsmark are presented. In addition, the losses in the cylinder walls were calculated using the models in Eurocode 2, which were modified based on the climatic conditions inside the reactor building. The results from the tendon force measurements showed that the prestress losses are low, between 5 % and 10 %, i.e. the margin to the lowest acceptable limit is currently sufficient. The effects of increasing the tendon forces were also investigated. Results from subsequent measurements on tendons where the tendon forces have been increased indicate that the development of the prestress losses may increase significantly when the tendon forces are increased to levels exceeding those of the original tensioning. The calculated prestress losses were in relatively good agreement with the measured losses, generally, the models somewhat overestimated the measured losses. (authors)

  9. Interactions between tenocytes and monosodium urate monohydrate crystals: implications for tendon involvement in gout.

    Science.gov (United States)

    Chhana, Ashika; Callon, Karen E; Dray, Michael; Pool, Bregina; Naot, Dorit; Gamble, Greg D; Coleman, Brendan; McCarthy, Geraldine; McQueen, Fiona M; Cornish, Jillian; Dalbeth, Nicola

    2014-09-01

    Advanced imaging studies have demonstrated that urate deposition in periarticular structures, such as tendons, is common in gout. The aim of this study was to investigate the effects of monosodium urate monohydrate (MSU) crystals on tenocyte viability and function. The histological appearance of tendons in joints affected by advanced gout was examined using light microscopy. In vitro, colorimetric assays and flow cytometry were used to assess cell viability in primary rat and primary human tenocytes cultured with MSU crystals. Real-time PCR was used to determine changes in the relative mRNA expression levels of tendon-related genes, and Sirius red staining was used to measure changes in collagen deposition in primary rat tenocytes. In joint samples from patients with gout, MSU crystals were identified within the tendon, adjacent to and invading into tendon, and at the enthesis. MSU crystals reduced tenocyte viability in a dose-dependent manner. MSU crystals decreased the mRNA expression of tendon collagens, matrix proteins and degradative enzymes and reduced collagen protein deposition by tenocytes. These data indicate that MSU crystals directly interact with tenocytes to reduce cell viability and function. These interactions may contribute to tendon damage in people with advanced gout. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  10. The roentgenographic findings of achilles tendon rupture

    Energy Technology Data Exchange (ETDEWEB)

    Seouk, Kang Hyo; Keun, Rho Yong [Shilla General Hospital, Seoul (Korea, Republic of)

    1999-03-01

    To evaluate the diagnostic value of a lateral view of the ankles in Achilles tendon rupture. We performed a retrospective analysis of the roentgenographic findings of 15 patients with surgically proven Achilles tendon rupture. Four groups of 15 patients(normal, ankle sprain, medial lateral malleolar fracture, and calcaneal fracture) were analysed as reference groups. Plain radiographs were reviewed with regard to Kager's triangle, Arner's sign, Toygar's angle, ill defined radiolucent shadow through the Achilles tendon, sharpness of the anterior margin of Achilles tendon, and meniscoid smooth margin of the posterior skin surface of the ankle. Kager's triangle was deformed and disappeared after rupture of the Achilles tendon in nine patients(60%) with operative verification of the rupture, six patients(40%) had a positive Arner's sign, while none had a diminished Toygars angle. In 13 patients(87%) with a ruptured Achilles tendon, the thickness of this was nonuniform compared with the reference group. The anterior margin of the Achilles tendon became serrated and indistinct in 14 patients(93%) in whom this was ruptured. An abnormal ill defined radiolucent shadow through the Achilles tendon was noted in nine patient(60%), and nonparallelism between the anterior margin of the Achilles tendon and posterior skin surface of the ankle was detected in 11 patients(73%). The posterior skin surface of the ankle had a nodular surface margin in 13 patients(87%). A deformed Kager's triangle and Achilles tendon, and an abnormal ill defined radiolucent shadow through the Achilles tendon in a lateral view of the ankles are important findings for the diagnesis of in diagnosing achilles tendon rupture.

  11. The roentgenographic findings of achilles tendon rupture

    International Nuclear Information System (INIS)

    Seouk, Kang Hyo; Keun, Rho Yong

    1999-01-01

    To evaluate the diagnostic value of a lateral view of the ankles in Achilles tendon rupture. We performed a retrospective analysis of the roentgenographic findings of 15 patients with surgically proven Achilles tendon rupture. Four groups of 15 patients(normal, ankle sprain, medial lateral malleolar fracture, and calcaneal fracture) were analysed as reference groups. Plain radiographs were reviewed with regard to Kager's triangle, Arner's sign, Toygar's angle, ill defined radiolucent shadow through the Achilles tendon, sharpness of the anterior margin of Achilles tendon, and meniscoid smooth margin of the posterior skin surface of the ankle. Kager's triangle was deformed and disappeared after rupture of the Achilles tendon in nine patients(60%) with operative verification of the rupture, six patients(40%) had a positive Arner's sign, while none had a diminished Toygars angle. In 13 patients(87%) with a ruptured Achilles tendon, the thickness of this was nonuniform compared with the reference group. The anterior margin of the Achilles tendon became serrated and indistinct in 14 patients(93%) in whom this was ruptured. An abnormal ill defined radiolucent shadow through the Achilles tendon was noted in nine patient(60%), and nonparallelism between the anterior margin of the Achilles tendon and posterior skin surface of the ankle was detected in 11 patients(73%). The posterior skin surface of the ankle had a nodular surface margin in 13 patients(87%). A deformed Kager's triangle and Achilles tendon, and an abnormal ill defined radiolucent shadow through the Achilles tendon in a lateral view of the ankles are important findings for the diagnesis of in diagnosing achilles tendon rupture

  12. * Fabrication and Characterization of Biphasic Silk Fibroin Scaffolds for Tendon/Ligament-to-Bone Tissue Engineering.

    Science.gov (United States)

    Font Tellado, Sònia; Bonani, Walter; Balmayor, Elizabeth R; Foehr, Peter; Motta, Antonella; Migliaresi, Claudio; van Griensven, Martijn

    2017-08-01

    Tissue engineering is an attractive strategy for tendon/ligament-to-bone interface repair. The structure and extracellular matrix composition of the interface are complex and allow for a gradual mechanical stress transfer between tendons/ligaments and bone. Thus, scaffolds mimicking the structural features of the native interface may be able to better support functional tissue regeneration. In this study, we fabricated biphasic silk fibroin scaffolds designed to mimic the gradient in collagen molecule alignment present at the interface. The scaffolds had two different pore alignments: anisotropic at the tendon/ligament side and isotropic at the bone side. Total porosity ranged from 50% to 80% and the majority of pores (80-90%) were ligament, enthesis, and cartilage markers significantly changed depending on pore alignment in each region of the scaffolds. In conclusion, the biphasic scaffolds fabricated in this study show promising features for tendon/ligament-to-bone tissue engineering.

  13. Field Evaluation of the System Identification Approach for Tension Estimation of External Tendons

    Directory of Open Access Journals (Sweden)

    Myung-Hyun Noh

    2015-01-01

    Full Text Available Various types of external tendons are considered to verify the applicability of tension estimation method based on the finite element model with system identification technique. The proposed method is applied to estimate the tension of benchmark numerical example, model structure, and field structure. The numerical and experimental results show that the existing methods such as taut string theory and linear regression method show large error in the estimated tension when the condition of external tendon is different with the basic assumption used during the derivation of relationship between tension and natural frequency. However, the proposed method gives reasonable results for all of the considered external tendons in this study. Furthermore, the proposed method can evaluate the accuracy of estimated tension indirectly by comparing the measured and calculated natural frequencies. Therefore, the proposed method can be effectively used for field application of various types of external tendons.

  14. Tendon sheath fibroma in the thigh.

    Science.gov (United States)

    Moretti, Vincent M; Ashana, Adedayo O; de la Cruz, Michael; Lackman, Richard D

    2012-04-01

    Tendon sheath fibromas are rare, benign soft tissue tumors that are predominantly found in the fingers, hands, and wrists of young adult men. This article describes a tendon sheath fibroma that developed in the thigh of a 70-year-old man, the only known tendon sheath fibroma to form in this location. Similar to tendon sheath fibromas that develop elsewhere, our patient's lesion presented as a painless, slow-growing soft tissue nodule. Physical examination revealed a firm, nontender mass with no other associated signs or symptoms. Although the imaging appearance of tendon sheath fibromas varies, our patient's lesion appeared dark on T1- and bright on T2-weighted magnetic resonance imaging. It was well marginated and enhanced with contrast.Histologically, tendon sheath fibromas are composed of dense fibrocollagenous stromas with scattered spindle-shaped fibroblasts and narrow slit-like vascular spaces. Most tendon sheath fibromas can be successfully removed by marginal excision, although 24% of lesions recur. No lesions have metastasized. Our patient's tendon sheath fibroma was removed by marginal excision, and the patient remained disease free 35 months postoperatively. Despite its rarity, tendon sheath fibroma should be included in the differential diagnosis of a thigh mass on physical examination or imaging, especially if it is painless, nontender, benign appearing, and present in men. Copyright 2012, SLACK Incorporated.

  15. Biology and augmentation of tendon-bone insertion repair

    OpenAIRE

    Lui, PPY; Zhang, P; Chan, KM; Qin, L

    2010-01-01

    Abstract Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL) reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis") which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be ...

  16. Differences in tendon properties in elite badminton players with or without patellar tendinopathy.

    Science.gov (United States)

    Couppé, C; Kongsgaard, M; Aagaard, P; Vinther, A; Boesen, M; Kjaer, M; Magnusson, S P

    2013-03-01

    The aim of this study was to examine the structural and mechanical properties of the patellar tendon in elite male badminton players with and without patellar tendinopathy. Seven players with unilateral patellar tendinopathy (PT group) on the lead extremity (used for forward lunge) and nine players with no current or previous patellar tendinopathy (CT group) were included. Magnetic resonance imaging was used to assess distal patellar tendon dimensions. Patellar tendon mechanical properties were assessed using simultaneous tendon force and deformation measurements. Distal tendon cross-sectional area (CSA) normalized for body weight (mm(2) /kg(2/3) ) was lower in the PT group compared with the CT group on both the non-lead extremity (6.1 ± 0.3 vs 7.4 ± 0.2, P < 0.05) and the lead extremity (6.5 ± 0.6 vs 8.4 ± 0.3, P < 0.05). Distal tendon stress was higher in the PT group compared with the CT group for both the non-lead extremity (31 ± 1 vs 27 ± 1 MPa, P < 0.05) and the lead extremity (32 ± 3 vs 21 ± 3 MPa, P < 0.01). Conclusively, the PT group had smaller distal patellar tendon CSA on both the injured (lead extremity) and the uninjured side (non-lead extremity) compared with the CT group. Subsequently, the smaller CSA yielded a greater distal patellar tendon stress in the PT group. Therefore, a small tendon CSA may predispose to the development of tendinopathy. © 2012 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  17. MRI findings of achilles tendon rupture

    International Nuclear Information System (INIS)

    Zhang Xuezhe

    2009-01-01

    Objective: To evaluate the MRI findings of achilles tendon rupture. Methods: The MRI data of 7 patients with achilles tendon rupture were retrospectively analysed. All 7 patients were male with the age ranging from 34 to 71 years. Routine MR scanning was performed in axial and sagittal planes, including T 1 WI, T 2 WI and a fat suppression MRI (SPIR). Results: Among 7 patients, complete achilles tendon rupture was seen in 6 cases, partial achilles tendon rupture 1 case. The site of tendon disruption were 2.6-11.0 cm( mean 5.4 cm) proximal to the insertion in the calcaneus. The MRI findings of a partial or complete rupture of the achilles tendon included enlarged and thickened achilles tendon (7 cases), wavy lax achilles tendon (2 cases), discontinuity of some or all of its fibers and intratendinous regions of increased signal intensity (7 cases). In the cases of complete tendon rupture, the size of the tendinous gap varied from 3.0-8.0 mm, which was filled with blood and appeared as edema of increase signal intensity on T 2 WI and SPIR. In all 7 patients, MR scanning showed medium signal intensity (7 cases) on T 1 WI, or medium signal intensity (1 cases), medium-high signal intensity (3 cases ), high signal intensity (3 cases) on T 2 WI, and medium-high signal intensity (2 cases), high signal intensity (5 cases) on fat suppression MRI. The preachilles fat pad showed obscure in 6 cases of complete achilles tendon rupture. Conclusion: MRI is an excellent method for revealing achilles tendon rupture and confirming the diagnosis. (authors)

  18. Tissue-engineering strategies for the tendon/ligament-to-bone insertion.

    Science.gov (United States)

    Smith, Lester; Xia, Younan; Galatz, Leesa M; Genin, Guy M; Thomopoulos, Stavros

    2012-01-01

    Injuries to connective tissues are painful and disabling and result in costly medical expenses. These injuries often require reattachment of an unmineralized connective tissue to bone. The uninjured tendon/ligament-to-bone insertion (enthesis) is a functionally graded material that exhibits a gradual transition from soft tissue (i.e., tendon or ligament) to hard tissue (i.e., mineralized bone) through a fibrocartilaginous transition region. This transition is believed to facilitate force transmission between the two dissimilar tissues by ameliorating potentially damaging interfacial stress concentrations. The transition region is impaired or lost upon tendon/ligament injury and is not regenerated following surgical repair or natural healing, exposing the tissue to risk of reinjury. The need to regenerate a robust tendon-to-bone insertion has led a number of tissue engineering repair strategies. This review treats the tendon-to-bone insertion site as a tissue structure whose primary role is mechanical and discusses current and emerging strategies for engineering the tendon/ligament-to-bone insertion in this context. The focus lies on strategies for producing mechanical structures that can guide and subsequently sustain a graded tissue structure and the associated cell populations.

  19. Self-monitoring surveillance system for prestressing tendons. Phase I small business innovation research

    International Nuclear Information System (INIS)

    Tabatabai, H.

    1995-12-01

    Assured safety and operational reliability of post-tensioned concrete components of nuclear power plants are of great significance to the public, electric utilities, and regulatory agencies. Prestressing tendons provide principal reinforcement for containment and other structures. In this phase of the research effort, the feasibility of developing a passive surveillance system for identification of ruptures in tendon wires was evaluated and verified. The concept offers high potential for greatly increasing effectiveness of presently-utilized periodic tendon condition surveillance programs. A one-tenth scale ring model of the Palo Verde nuclear containment structure was built inside the Structural Laboratory. Dynamic scaling (similitude) relationships were used to relate measured sensor responses recorded during controlled wire breakages to the expected prototype containment tendon response. Strong and recognizable signatures were detected by the accelerometers used. It was concluded that the unbonded prestressing tendons provide an excellent path for transmission of stress waves resulting from wire breaks. Accelerometers placed directly on the bearing plates at the ends of tendons recorded high-intensity waveforms. Accelerometers placed elsewhere on concrete surfaces of the containment model revealed substantial attenuation and reduced intensities of captured waveforms. Locations of wire breaks could be determined accurately through measurement of differences in arrival times of the signal at the sensors. Pattern recognition systems to be utilized in conjunction with the proposed concept will provide a basis for an integrated and automated tool for identification of wire breaks

  20. High-resolution study of the 3D collagen fibrillary matrix of Achilles tendons without tissue labelling and dehydrating.

    Science.gov (United States)

    Wu, Jian-Ping; Swift, Benjamin John; Becker, Thomas; Squelch, Andrew; Wang, Allan; Zheng, Yong-Chang; Zhao, Xuelin; Xu, Jiake; Xue, Wei; Zheng, Minghao; Lloyd, David; Kirk, Thomas Brett

    2017-06-01

    Knowledge of the collagen structure of an Achilles tendon is critical to comprehend the physiology, biomechanics, homeostasis and remodelling of the tissue. Despite intensive studies, there are still uncertainties regarding the microstructure. The majority of studies have examined the longitudinally arranged collagen fibrils as they are primarily attributed to the principal tensile strength of the tendon. Few studies have considered the structural integrity of the entire three-dimensional (3D) collagen meshwork, and how the longitudinal collagen fibrils are integrated as a strong unit in a 3D domain to provide the tendons with the essential tensile properties. Using second harmonic generation imaging, a 3D imaging technique was developed and used to study the 3D collagen matrix in the midportion of Achilles tendons without tissue labelling and dehydration. Therefore, the 3D collagen structure is presented in a condition closely representative of the in vivo status. Atomic force microscopy studies have confirmed that second harmonic generation reveals the internal collagen matrix of tendons in 3D at a fibril level. Achilles tendons primarily contain longitudinal collagen fibrils that braid spatially into a dense rope-like collagen meshwork and are encapsulated or wound tightly by the oblique collagen fibrils emanating from the epitenon region. The arrangement of the collagen fibrils provides the longitudinal fibrils with essential structural integrity and endows the tendon with the unique mechanical function for withstanding tensile stresses. A novel 3D microscopic method has been developed to examine the 3D collagen microstructure of tendons without tissue dehydrating and labelling. The study also provides new knowledge about the collagen microstructure in an Achilles tendon, which enables understanding of the function of the tissue. The knowledge may be important for applying surgical and tissue engineering techniques to tendon reconstruction. © 2017 The Authors

  1. The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model

    OpenAIRE

    Li, Shengkun; Ma, Kui; Li, Hong; Jiang, Jia; Chen, Shiyi

    2016-01-01

    The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET) artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA) is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired w...

  2. Firm anchoring between a calcium phosphate-hybridized tendon and bone for anterior cruciate ligament reconstruction in a goat model

    Energy Technology Data Exchange (ETDEWEB)

    Mutsuzaki, Hirotaka [Department of Orthopaedic Surgery, Ibaraki Prefectural University of Health Sciences, 4669-2 Ami Ami-machi, Inashiki-gun, Ibaraki 300-0394 (Japan); Sakane, Masataka; Ochiai, Naoyuki [Department of Orthopaedic Surgery, Institute of Clinical Medicine, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575 (Japan); Hattori, Shinya; Kobayashi, Hisatoshi, E-mail: sakane-m@md.tsukuba.ac.j [Biomaterial Center, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2009-08-15

    Using an alternative soaking process improved the tendon-bone attachment for a calcium phosphate (CaP)-hybridized tendon graft. We characterized the deposited CaP on and in tendons and analyzed the histology and mechanical properties of the tendon-bone interface in anterior cruciate ligament (ACL) reconstruction in goats. The tendon grafts to be implanted were soaked ten times alternately in a Ca-containing solution and a PO{sub 4}-containing solution for 30 s each. Needlelike CaP nanocrystals including low-crystalline apatite were deposited on and between collagen fibrils from the surface to a depth of 200{mu}m inside the tendon. The structure resembles the extracellular matrix of bone. In animal experiments, the CaP-hybridized tendon directly bonded with newly formed bone at 6 weeks (n = 3), while fibrous bonding was observed in the control (n = 3). The ultimate failure load was not statistically different between the CaP (n = 7) and control (n = 7). However, in the failure mode, all the tendon-bone interfaces were intact in the CaP group, while three of seven specimens were pulled out from bone tunnels in the control. The result suggested that the strength of the tendon-bone interface in the CaP group is superior to that in the control group. Clinically, firm tendon-bone anchoring may lead to good results without the knee instability associated with the loosening of the bone-tendon junction in ACL reconstruction.

  3. Mechanical properties and collagen cross-linking of the patellar tendon in old and young men

    DEFF Research Database (Denmark)

    Couppé, C; Hansen, P; Kongsgaard, M

    2009-01-01

    were higher in OM than in YM (73 +/- 13 vs. 11 +/- 2 mmol/mol; P appreciably influence the dimensions or mechanical properties of the human patellar tendon in vivo. Collagen concentration was reduced, whereas both enzymatic......Age-related loss in muscle mass and strength impairs daily life function in the elderly. However, it remains unknown whether tendon properties also deteriorate with age. Cross-linking of collagen molecules provides structural integrity to the tendon fibrils and has been shown to change with age...... in animals but has never been examined in humans in vivo. In this study, we examined the mechanical properties and pyridinoline and pentosidine cross-link and collagen concentrations of the patellar tendon in vivo in old (OM) and young men (YM). Seven OM (67 +/- 3 years, 86 +/- 10 kg) and 10 YM (27 +/- 2...

  4. Simulation of tendon energy storage in pedaling

    DEFF Research Database (Denmark)

    Rasmussen, John; Damsgaard, Michael; Christensen, Søren Tørholm

    2001-01-01

    The role of elastic energy stored in tendons during pedaling is investigated by means of numerical simulation using the AnyBody body modeling system. The loss of metabolic energy due to tendon elasticity is computed and compared to the mechanical work involved in the process. The AnyBody simulati...

  5. Rupture of Achilles Tendon : Usefulness of Ultrasonography

    International Nuclear Information System (INIS)

    Kim, Nam Hyeon; Ki, Won Woo; Yoon, Kwon Ha; Kim, Song Mun; Shin, Myeong Jin; Kwon, Soon Tae

    1996-01-01

    To differentiate a complete rupture of Achilles tendon from an incomplete one which is important because its treatment is quite different. And it is necessary to know the exact site of the rupture preoperatively. Fifteen cases of fourteen patients which were diagnosed as Achilles tendon rupture by ultrasonography and surgery were reviewed. We compared sonographic rupture site with surgical findings. Ultrasonographic criteria for differentiation of complete and incomplete rupture was defined as follows : the discreteness, which means the proximal intervening hypoechogenicity to the interface echogenicity of distal margin of ruptured tendon : the slant sign, which represents the interface of ruptured distal margin which was seen over the 3/4 of the thickness of the tendon without intervening low echogeneicity : the invagination sign, which means the echogenic invagination from Kager triangle into posterior aspect of Achilles tendon over the half thickness of the tendon. The sites of complete tendon rupture were exactly corresponded to surgical finding in four cases of ten complete ruptures. And the discrepancy between sonographic and surgical findings in the site of complete rupture was 1.2 ± 0.4 cm in six cases. Three of ten complete ruptures showed the discreteness sign, all of ten showed the slant sign and two of ten showed the invagination sign. It is helpful to differentiate a complete from incomplete rupture of the Achilles tendon and to localize the site of the complete rupture with the ultrasonographic evaluation

  6. Measuring Regional Changes in Damaged Tendon

    Science.gov (United States)

    Frisch, Catherine Kayt Vincent

    Mechanical properties of tendon predict tendon health and function, but measuring these properties in vivo is difficult. An ultrasound-based (US) analysis technique called acoustoelastography (AE) uses load-dependent changes in the reflected US signal to estimate tissue stiffness non-invasively. This thesis explores whether AE can provide information about stiffness alteration resulting from tendon tears both ex vivo and in vivo. An ex vivo ovine infraspinatus tendon model suggests that the relative load transmitted by the different tendon layers transmit different fractions of the load and that ultrasound echo intensity change during cyclic loading decreases, becoming less consistent once the tendon is torn. An in vivo human tibialis anterior tendon model using electrically stimulated twitch contractions investigated the feasibility of measuring the effect in vivo. Four of the five subjects showed the expected change and that the muscle contraction times calculated using the average grayscale echo intensity change compared favorably with the times calculated based on the force data. Finally an AE pilot study with patients who had rotator cuff tendon tears found that controlling the applied load and the US view of the system will be crucial to a successful in vivo study.

  7. Bilateral synchronous rupture of the quadriceps tendon.

    LENUS (Irish Health Repository)

    Ellanti, P

    2012-09-01

    Bilateral simultaneous rupture of the quadriceps tendon is a rare entity. They are often associated with degenerative changes of the tendons and predisposing conditions such as diabetes or excessive steroid use. They most commonly tend to occur in patients of 40 years of age or older.

  8. Effects of plyometric and isometric training on muscle and tendon stiffness in vivo.

    Science.gov (United States)

    Kubo, Keitaro; Ishigaki, Tomonobu; Ikebukuro, Toshihiro

    2017-08-01

    The purpose of this study was to compare the effects of plyometric and isometric training on tendon properties during ramp and ballistic contractions and muscle stiffness under passive and active conditions. Eleven subjects completed 12 weeks (3 days/week) of a unilateral training program for the plantar flexors. They performed plyometric training on one side (PLY) and isometric training on the other side (ISO). Active muscle stiffness in the medial gastrocnemius muscle was calculated according to changes in estimated muscle force and fascicle length during fast stretching after submaximal isometric contractions. Passive muscle stiffness was also calculated from estimated passive muscle force and fascicle length during slow passive stretching. Stiffness and hysteresis of tendon structures were measured using ultrasonography during ramp and ballistic contractions. Passive muscle stiffness and tendon hysteresis did not change for PLY or ISO Active muscle stiffness significantly increased for PLY, but not for ISO Tendon stiffness during ramp and ballistic contractions increased significantly for ISO, but not for PLY In addition, tendon elongation values at force production levels beyond 100 N during ballistic contractions increased for PLY These results suggest that plyometric training (but not isometric training) enhances the extensibility of tendon structures during ballistic contractions and active muscle stiffness during fast stretching, and these changes may be related to improved performances during stretch-shortening cycle exercises. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  9. Therapeutic potential of mesenchymal stem cells to treat Achilles tendon injuries.

    Science.gov (United States)

    Vieira, M H C; Oliveira, R J; Eça, L P M; Pereira, I S O; Hermeto, L C; Matuo, R; Fernandes, W S; Silva, R A; Antoniolli, A C M B

    2014-12-12

    Rupture of the Achilles tendon diminishes quality of life. The gold-standard therapy is a surgical suture, but this presents complications, including wound formation and inflammation. These complications spurred evaluation of the therapeutic potential of mesenchymal stem cells (MSCs) from adipose tissue. New Zealand rabbits were divided into 6 groups (three treatments with two time points each) evaluated at either 14 or 28 days after surgery: cross section of the Achilles tendon (CSAT); CSAT + Suture; and CSAT + MSC. A comparison between all groups at both time points showed a statistically significant increase in capillaries and in the structural organization of collagen in the healed tendon in the CSAT + Suture and CSAT + MSC groups at the 14-day assessment. Comparison between the two time points within the same group showed a statistically significant decrease in the inflammatory process and an increase in the structural organization of collagen in the CSAT and CSAT + MSC groups. A study of the genomic integrity of the cells suggested a linear correlation between an increase of injuries and culture time. Thus, MSC transplantation is a good alternative for treatment of Achilles tendon ruptures because it may be conducted without surgery and tendon suture and, therefore, has no risk of adverse effects resulting from the surgical wound or inflammation caused by nonabsorbable sutures. Furthermore, this alternative treatment exhibits a better capacity for wound healing and maintaining the original tendon architecture, depending on the arrangement of the collagen fibers, and has important therapeutic potential.

  10. GH receptor blocker administration and muscle-tendon collagen synthesis in humans

    DEFF Research Database (Denmark)

    Nielsen, Rie Harboe; Doessing, Simon; Goto, Kazushige

    2011-01-01

    Collagen is the predominant structural protein in tendons and ligaments, and can be controlled by hormonal changes. In animals, injections of insulin-like growth factor I (IGF-I) has been shown to increase collagen synthesis in tendons and ligaments and to improve structural tissue healing......, but the effect of local IGF-I administration on tendon collagen synthesis in human has not been studied. The purpose of this study was to study whether local injections of IGF-I would have a stimulating effect on tendon collagen synthesis. Twelve healthy nonsmoking men [age 62 ± 1 years (mean ± SEM), BMI 27 ± 1......] participated. Two injections of either human recombinant IGF-I (0.1 mL Increlex©) or saline (control) into each patellar tendon were performed 24-h apart, respectively. Tendon collagen fractional synthesis rate (FSR) was measured by stable isotope technique in the hours after the second injection...

  11. Effects of flunixin meglumine on experimental tendon wound healing: A histopathological and mechanical study in rabbits

    Directory of Open Access Journals (Sweden)

    Mehdi Behfar

    2014-12-01

    Full Text Available Tendons are frequently targets of injury in sports and work. Whether nonsteroidal anti-inflammatory drugs (NSAIDs have beneficial effects on tendon healing is still a matter of debate. This study was conducted to evaluate effects of flunixin meglumine (FM on tendon healing after experimentally induced acute trauma. Twenty eight adult male New Zealand White rabbits were subjected to complete transection of deep digital flexor tendons followed by suture placement. Treatment group received intramuscular injection of FM for three days, and controls received placebo. Subsequently, cast immobilization was continued for two weeks. Animals were sacrificed four weeks after surgery and tissue samples were taken. The histological evaluations revealed improved structural characteristics of neotendon formation including fibrillar linearity, fibrillar continuity and neovascularization in treatment group compared to those of controls (p 0.05. Mechanical evaluation revealed significant increase in load-related material properties including ultimate load, yield load, energy absorption and ultimate stress in treatment group compared to those of control group (p 0.05. The present study showed that intramuscular injection of FM resulted in improved structural and mechanical properties of tendon repairs and it could be an effective treatment for acute tendon injuries like severance and laceration.

  12. Functional grading of mineral and collagen in the attachment of tendon to bone.

    Science.gov (United States)

    Genin, Guy M; Kent, Alistair; Birman, Victor; Wopenka, Brigitte; Pasteris, Jill D; Marquez, Pablo J; Thomopoulos, Stavros

    2009-08-19

    Attachment of dissimilar materials is a major challenge because high levels of localized stress may develop at their interfaces. An effective biologic solution to this problem exists at one of nature's most extreme interfaces: the attachment of tendon (a compliant, structural "soft tissue") to bone (a stiff, structural "hard tissue"). The goal of our study was to develop biomechanical models to describe how the tendon-to-bone insertion derives its mechanical properties. We examined the tendon-to-bone insertion and found two factors that give the tendon-to-bone transition a unique grading in mechanical properties: 1), a gradation in mineral concentration, measured by Raman spectroscopy; and 2), a gradation in collagen fiber orientation, measured by polarized light microscopy. Our measurements motivate a new physiological picture of the tissue that achieves this transition, the tendon-to-bone insertion, as a continuous, functionally graded material. Our biomechanical model suggests that the experimentally observed increase in mineral accumulation within collagen fibers can provide significant stiffening of the partially mineralized fibers, but only for concentrations of mineral above a "percolation threshold" corresponding to formation of a mechanically continuous mineral network within each collagen fiber (e.g., the case of mineral connectivity extending from one end of the fiber to the other). Increasing dispersion in the orientation distribution of collagen fibers from tendon to bone is a second major determinant of tissue stiffness. The combination of these two factors may explain the nonmonotonic variation of stiffness over the length of the tendon-to-bone insertion reported previously. Our models explain how tendon-to-bone attachment is achieved through a functionally graded material composition, and provide targets for tissue engineered surgical interventions and biomimetic material interfaces.

  13. Quantitative tissue parameters of Achilles tendon and plantar fascia in healthy subjects using a handheld myotonometer.

    Science.gov (United States)

    Orner, Sarah; Kratzer, Wolfgang; Schmidberger, Julian; Grüner, Beate

    2018-01-01

    The aim of the study was to examine the quantitative tissue properties of the Achilles tendon and plantar fascia using a handheld, non-invasive MyotonPRO device, in order to generate normal values and examine the biomechanical relationship of both structures. Prospective study of a large, healthy sample population. The study sample included 207 healthy subjects (87 males and 120 females) for the Achilles tendon and 176 healthy subjects (73 males and 103 females) for the plantar fascia. For the correlations of the tissue parameters of the Achilles tendon and plantar fascia an intersection of both groups was formed which included 150 healthy subjects (65 males and 85 females). All participants were measured in a prone position. Consecutive measurements of the Achilles tendon and plantar fascia were performed by MyotonPRO device at defined sites. For the left and right Achilles tendons and plantar fasciae all five MyotonPRO parameters (Frequency [Hz], Decrement, Stiffness [N/m], Creep and Relaxation Time [ms]) were calculated of healthy males and females. The correlation of the tissue parameters of the Achilles tendon and plantar fascia showed a significant positive correlation of all parameters on the left as well as on the right side. The MyotonPRO is a feasible device for easy measurement of passive tissue properties of the Achilles tendon and plantar fascia in a clinical setting. The generated normal values of the Achilles tendon and plantar fascia are important for detecting abnormalities in patients with Achilles tendinopathy or plantar fasciitis in the future. Biomechanically, both structures are positively correlated. This may provide new aspects in the diagnostics and therapy of plantar fasciitis and Achilles tendinopathy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Sonography findings in tears of the extensor pollicis longus tendon and correlation with CT, MRI and surgical findings

    International Nuclear Information System (INIS)

    Ruiz Santiago, Fernando; Garofano Plazas, Pilar; Fernandez, Juan Miguel Tristan

    2008-01-01

    We present our experience in the diagnosis of extensor pollicis longus tendon tears using different imaging methods. In the past 2 years, 12 patients (7 males, 5 females) with extension deficit of distal phalanx of thumb were diagnosed with extensor pollicis longus tendon (EPL) rupture by means of different imaging methods. The ultrasound pattern consisted of a gap between tendon stumps occupied by a continuous (eight cases) or discontinuous (four cases) attenuated hypoechoic string. In nine cases, the tendon ends were identified as a thickened stump-like structure. In the other three cases, tendon stumps were attenuated and mixed with atrophic muscle or wrist subcutaneous fat. All ultrasound findings were confirmed by CT, MR and/or surgical findings

  15. Thompson Test in Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Spencer Albertson

    2016-07-01

    Full Text Available HPI: A 26-year old male presented to the emergency department after experiencing the acute onset of left ankle pain while playing basketball. Upon jumping, he felt a “pop” in his left posterior ankle, followed by pain and difficulty ambulating. His exam was notable for a defect at the left Achilles tendon on palpation. The practitioner performed a Thompson test, which was positive (abnormal on the left. Significant Findings: The left Achilles tendon had a defect on palpation, while the right Achilles tendon was intact. When squeezing the right (unaffected calf, the ankle spontaneously plantar flexed, indicating a negative (normal Thompson test. Upon squeeze of the left (affected calf, the ankle did not plantar flex, signifying a positive (abnormal Thompson test. The diagnosis of left Achilles tendon rupture was confirmed intraoperatively one week later. Discussion: The Achilles tendon (also: calcaneal tendon or heel cord is derived from the medial and lateral heads of the gastrocnemius muscle, as well as the soleus muscle. Rupture of the Achilles tendon most commonly occurs in the distal tendon, approximately 2-6 cm from its attachment to the calcaneal tuberosity, in an area of hypovascularity known as the “watershed” or “critical” zone.1-3 The Thompson test (also: Simmonds-Thompson test, described by Simmonds in 1957 and Thompson in 1962, is done while the patient is in the prone position, with feet hanging over the end of a table/gurney, or with the patient kneeling on a stool or chair.4-5 Squeezing the calf of an unaffected limb will cause the ankle to plantar flex, but squeezing the calf of a limb with an Achilles tendon rupture will cause no motion. The sensitivity of the Thompson’s test for the diagnosis of a complete Achilles tendon rupture is 96-100% and the specificity is 93-100%, but data is limited.6-8

  16. Achillodynia. Radiological imaging of acute and chronic overuse injuries of the Achilles tendon; Achillodynie. Radiologische Bildgebung bei akuten und chronischen Ueberlastungsschaeden der Achillessehne

    Energy Technology Data Exchange (ETDEWEB)

    Syha, R.; Springer, F.; Grosse, U. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology; Tuebingen Univ. (Germany). Section on Experimental Radiology; Ketelsen, D.; Kramer, U.; Horger, M. [Tuebingen Univ. (Germany). Diagnostic and Interventional Radiology; Ipach, I. [University Hospital Tuebingen (Germany). Orthopaedic Surgery; Schick, F. [Tuebingen Univ. (Germany). Section on Experimental Radiology

    2013-11-15

    In the past decades the incidence of acute and chronic disorders of the Achilles tendon associated with sport-induced overuse has steadily increased. Besides acute complete or partial ruptures, achillodynia (Achilles tendon pain syndrome), which is often associated with tendon degeneration, represents the most challenging entity regarding clinical diagnostics and therapy. Therefore, the use of imaging techniques to differentiate tendon disorders and even characterize structure alterations is of growing interest. This review article discusses the potential of different imaging techniques with respect to the diagnosis of acute and chronic tendon disorders. In this context, the most commonly used imaging techniques are magnetic resonance imaging (MRI), B-mode ultrasound, and color-coded Doppler ultrasound (US). These modalities allow the detection of acute tendon ruptures and advanced chronic tendon disorders. However, the main disadvantages are still the low capabilities in the detection of early-stage degeneration and difficulties in the assessment of treatment responses during follow-up examinations. Furthermore, differentiation between chronic partial ruptures and degeneration remains challenging. The automatic contour detection and texture analysis may allow a more objective and quantitative interpretation, which might be helpful in the monitoring of tendon diseases during follow-up examinations. Other techniques to quantify tendon-specific MR properties, e.g. based on ultrashort echo time (UTE) sequences, also seem to have great potential with respect to the precise detection of degenerative tendon disorders and their differentiation at a very early stage. (orig.)

  17. Analysis study on change of tendon behavior during pressurization process of Pre-stressed Concrete Containment Vessel

    International Nuclear Information System (INIS)

    Kashiwase, Takako; Nagasaka, Hideo

    1999-01-01

    NUPEC has been planning the ultimate strength test of Pre-stressed Concrete Containment Vessel (PCCV). The test model is 1/4 uniform scale model of Japan actual PCCV. It involves an equipment hatch, several penetrations and liner with T-anchors. The ancillary test for the PCCV test was conducted, in which friction coefficient of hoop tendon was evaluated by tensile force distribution using the same tendon as that of 1/4 PCCV model. Tendon will be in plastic region under internal pressure above 3.5 times design pressure (Pd) and surface characteristic of tendon and the resultant friction coefficient will be changed. In the present paper, tendon friction coefficient in the plastic region was obtained by evaluating plastic region data of tendon in the ancillary test. The validity of the obtained friction coefficient was confirmed by the tendon elongation data. In addition to the formally developed elastic region friction coefficient, the obtained plastic region correlation was incorporated into ABAQUS Ver. 5.6. The effect of tendon tensile force distribution change on structural behavior up to 3.8 Pd was evaluated. (author)

  18. Histological study of the influence of plasma rich in growth factors (PRGF) on the healing of divided Achilles tendons in sheep.

    Science.gov (United States)

    Fernández-Sarmiento, J Andrés; Domínguez, Juan M; Granados, María M; Morgaz, Juan; Navarrete, Rocío; Carrillo, José M; Gómez-Villamandos, Rafael J; Muñoz-Rascón, Pilar; Martín de Las Mulas, Juana; Millán, Yolanda; García-Balletbó, Montserrat; Cugat, Ramón

    2013-02-06

    The use of plasma rich in growth factors (PRGF) has been proposed to improve the healing of Achilles tendon injuries, but there is debate about the effectiveness of this therapy. The objective of the present study was to evaluate the histological effects of PRGF, which is a type of leukocyte-poor platelet-rich plasma, on tendon healing. The Achilles tendons of twenty-eight sheep were divided surgically. The animals were randomly divided into four groups of seven animals each. The repaired tendons in two groups received an infiltration of PRGF intraoperatively and every week for the following three weeks under ultrasound guidance. The tendons in the other two groups received injections with saline solution. The animals in one PRGF group and one saline solution group were killed at four weeks, and the animals in the remaining two groups were killed at eight weeks. The Achilles tendons were examined histologically, and the morphometry of fibroblast nuclei was calculated. The fibroblast nuclei of the PRGF-treated tendons were more elongated and more parallel to the tendon axis than the fibroblast nuclei of the tendons in the saline solution group at eight weeks. PRGF-treated tendons showed more packed and better oriented collagen bundles at both four and eight weeks. In addition to increased maturation of the collagen structure, fibroblast density was significantly lower in PRGF-infiltrated tendons. PRGF-treated tendons exhibited faster vascular regression than tendons in the control groups, as demonstrated by a lower vascular density at eight weeks. PRGF was associated with histological changes consistent with an accelerated early healing process in repaired Achilles tendons in sheep after experimental surgical disruption. PRGF-treated tendons showed improvements in the morphometric features of fibroblast nuclei, suggesting a more advanced stage of healing. At eight weeks, histological examination revealed more mature organization of collagen bundles, lower vascular

  19. Serial superficial digital flexor tendon biopsies for diagnosing and monitoring collagenase-induced tendonitis in horses

    Directory of Open Access Journals (Sweden)

    José C. de Lacerda Neto

    2013-06-01

    Full Text Available The purpose of this investigation was to demonstrate the feasibility of a biopsy technique by performing serial evaluations of tissue samples of the forelimb superficial digital flexor tendon (SDFT in healthy horses and in horses subjected to superficial digital flexor tendonitis induction. Eight adult horses were evaluated in two different phases (P, control (P1 and tendonitis-induced (P2. At P1, the horses were subjected to five SDFT biopsies of the left forelimb, with 24 hours (h of interval. Clinical and ultrasonographic (US examinations were performed immediately before the tendonitis induction, 24 and 48 h after the procedure. The biopsied tendon tissues were analyzed through histology. P2 evaluations were carried out three months later, when the same horses were subjected to tendonitis induction by injection of bacterial collagenase into the right forelimb SDFT. P2 clinical and US evaluations, and SDFT biopsies were performed before, and after injury induction at the following time intervals: after 24, 48, 72 and 96 h, and after 15, 30, 60, 90, 120 and 150 days. The biopsy technique has proven to be easy and quick to perform and yielded good tendon samples for histological evaluation. At P1 the horses did not show signs of localised inflammation, pain or lameness, neither SDFT US alterations after biopsies, showing that the biopsy procedure per se did not risk tendon integrity. Therefore, this procedure is feasible for routine tendon histological evaluations. The P2 findings demonstrate a relation between the US and histology evaluations concerning induced tendonitis evolution. However, the clinical signs of tendonitis poorly reflected the microscopic tissue condition, indicating that clinical presentation is not a reliable parameter for monitoring injury development. The presented method of biopsying SDFT tissue in horses enables the serial collection of material for histological analysis causing no clinical signs and tendon damage seen

  20. Achilles tendon: US diagnosis of pathologic conditions. Work in progress

    International Nuclear Information System (INIS)

    Blei, C.L.; Nirschl, R.P.; Grant, E.G.

    1986-01-01

    Twenty-three patients were prospectively examined with ultra-sound (US) for acute or recurrent Achilles tendon symptoms. Three types of pathologic conditions of the Achilles tendon were found: tendinitis/tenosynovitis, acute tendon trauma, and postoperative changes. US appears to enable differentiation of these conditions and to contribute to the diagnosis of a broad range of Achilles tendon disorders

  1. Achilles tendon: US diagnosis of pathologic conditions. Work in progress

    Energy Technology Data Exchange (ETDEWEB)

    Blei, C.L.; Nirschl, R.P.; Grant, E.G.

    1986-06-01

    Twenty-three patients were prospectively examined with ultra-sound (US) for acute or recurrent Achilles tendon symptoms. Three types of pathologic conditions of the Achilles tendon were found: tendinitis/tenosynovitis, acute tendon trauma, and postoperative changes. US appears to enable differentiation of these conditions and to contribute to the diagnosis of a broad range of Achilles tendon disorders.

  2. Micromechanical properties and collagen composition of ruptured human achilles tendon

    DEFF Research Database (Denmark)

    Hansen, Philip; Kovanen, Vuokko; Hölmich, Per

    2013-01-01

    The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive.......The Achilles tendon is one of the strongest tendons in the human body, and yet it frequently ruptures, which is a substantial clinical problem. However, the cause of ruptures remains elusive....

  3. Region-specific mechanical properties of the human patella tendon

    DEFF Research Database (Denmark)

    Haraldsson, B T; Aagaard, P; Krogsgaard, M

    2004-01-01

    The present study investigated the mechanical properties of tendon fascicles from the anterior and posterior human patellar tendon. Collagen fascicles from the anterior and posterior human patellar tendon in healthy young men (mean +/- SD, 29.0 +/- 4.6 yr, n = 6) were tested in a mechanical rig...... portion of the tendon, indicating region-specific material properties....

  4. Osmotic pressure induced tensile forces in tendon collagen.

    Science.gov (United States)

    Masic, Admir; Bertinetti, Luca; Schuetz, Roman; Chang, Shu-Wei; Metzger, Till Hartmut; Buehler, Markus J; Fratzl, Peter

    2015-01-22

    Water is an important component of collagen in tendons, but its role for the function of this load-carrying protein structure is poorly understood. Here we use a combination of multi-scale experimentation and computation to show that water is an integral part of the collagen molecule, which changes conformation upon water removal. The consequence is a shortening of the molecule that translates into tensile stresses in the range of several to almost 100 MPa, largely surpassing those of about 0.3 MPa generated by contractile muscles. Although a complete drying of collagen would be relevant for technical applications, such as the fabrication of leather or parchment, stresses comparable to muscle contraction already occur at small osmotic pressures common in biological environments. We suggest, therefore, that water-generated tensile stresses may play a role in living collagen-based materials such as tendon or bone.

  5. High-field MR imaging of the tendons

    International Nuclear Information System (INIS)

    Beltran, J.; Burk, J.M.; Herman, L.J.; Mosure, J.C.

    1987-01-01

    MR imaging was used to investigate normal anatomy and pathologic conditions of the tendons. Tendons of experimental animals, cadaver joints, normal volunteers, and patients with suspected tendon pathology were studied. Tendon anatomy is easily identified because of the hypointensity of the tendons contrasting with the hyperintendensity of the surrounding fat. Pathologic conditions including posttraumatic and postsurgical tendon rupture, peritendinous scarring, tendinitis, and tenosynovitis are well seen with MR imaging. A detailed study of normal and abnormal tendon anatomy of the finger, wrist, shoulder, knee, and ankle is displayed, including MR images, gross specimens, and line drawings

  6. Shortened stapedius tendon: a rare cause of conductive hearing loss.

    Science.gov (United States)

    Zawawi, F; Varshney, R; Schloss, M D

    2014-01-01

    Anomalies of the stapedius tendon have been reported to cause conductive hearing loss; in theory, such anomalies limit the movement of the stapes. To demonstrate a rare cause of conductive hearing loss resulting from anomaly of the stapedius tendon and to compare the clinical findings of this patient to other stapedius tendon anomalies reported in the literature. Case report of a single case of shortened stapedius tendon and a review of the English literature on stapedius tendon anomalies. This is a case report of a 15-year-old boy with shortened stapedius tendon causing unilateral hearing loss, accompanied by a review of the literature. Contrary to other reported cases, this patient did not have an ossified tendon, but rather an extremely short tendon. The boy regained normal hearing following excision of the stapedius tendon. A shortened stapedius tendon is a very rare diagnosis, yet it should be considered as a possible cause of conductive hearing loss.

  7. Effect of the Interposition of Calcium Phosphate Materials on Tendon-Bone Healing During Repair of Chronic Rotator Cuff Tear.

    Science.gov (United States)

    Zhao, Song; Peng, Lingjie; Xie, Guoming; Li, Dingfeng; Zhao, Jinzhong; Ning, Congqin

    2014-08-01

    The current nature of tendon-bone healing after rotator cuff (RC) repair is still the formation of granulation tissue at the tendon-bone interface rather than the formation of fibrocartilage, which is the crucial structure in native tendon insertion and can be observed after knee ligament reconstruction. The interposition of calcium phosphate materials has been found to be able to enhance tendon-bone healing in knee ligament reconstruction. However, whether the interposition of these kinds of materials can enhance tendon-bone healing or even change the current nature of tendon-bone healing after RC repair still needs to be explored. The interposition of calcium phosphate materials during RC repair would enhance tendon-bone healing or change its current nature of granulation tissue formation into a more favorable process. Controlled laboratory study. A total of 144 male Sprague-Dawley rats underwent unilateral detachment of the supraspinatus tendon, followed by delayed repair after 3 weeks. The animals were allocated into 1 of 3 groups: (1) repair alone, (2) repair with Ca5(PO4)2SiO4 (CPS) bioceramic interposition, or (3) repair with hydroxyapatite (HA) bioceramic interposition at the tendon-bone interface. Animals were sacrificed at 2, 4, or 8 weeks postoperatively, and microcomputed tomography (micro-CT) was used to quantify the new bone formation at the repair site. New fibrocartilage formation and collagen organization at the tendon-bone interface was evaluated by histomorphometric analysis. Biomechanical testing of the supraspinatus tendon-bone complex was performed. Statistical analysis was performed using 1-way analysis of variance. Significance was set at P repair, CPS bioceramic significantly increased the area of fibrocartilage at the tendon-bone interface compared with the control and HA groups. Moreover, CPS and HA bioceramics had significantly improved collagen organization. Biomechanical tests indicated that the CPS and HA groups have greater ultimate

  8. Fibroma of the tendon sheath of the long head of the biceps tendon

    International Nuclear Information System (INIS)

    Maeseneer, Michel de; Shahabpour, Maryam; Isacker, Tom van; Lenchik, Leon; Caillie, Marie-Astrid van

    2014-01-01

    Fibroma of the tendon sheath is a benign tumor that is less common than giant cell tumor of the tendon sheath. Both tumors may present as a painless, slowly enlarging mass. Radiological findings may be similar for both tumors. Histologically, fibroma of the tendon sheath lacks the hemosiderin-laden macrophages that are typical for giant cell tumor of the tendon sheath. We report on a 49-year-old woman with fibroma of the tendon sheath of the long head of the biceps tendon. In our case, on MR images, we observed band-like hypointense areas centrally in the tumor, mild patchy contrast enhancement, and most importantly, no decrease of signal intensity on gradient echo images. These characteristics reflected histological findings. (orig.)

  9. Finite Element Analysis of Grouting Compactness Monitoring in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers

    Directory of Open Access Journals (Sweden)

    Tianyong Jiang

    2017-09-01

    Full Text Available With the development of the post-tensioning technique, prestressed concrete structures have been widely used in civil engineering. To ensure the long-term effectiveness of the prestressed tendon, the grouting quality of the tendon duct is one of the important factors. However, it is still a challenge to monitor the grouting quality of post-tensioning tendon ducts, due to the invisibility of the grouting. The authors’ previous work proposed a real-time method that employed a stress wave-based active sensing approach with piezoceramic transducers to monitor the grouting compactness of a Post-Tensioning Tendon Duct (PTTD. To further understand the piezoceramic induced stress wave propagation in the PTTD with different grouting levels, this paper develops a two-dimensional finite element model for monitoring the grouting compactness of the tendon duct with a piezoceramic transducer. A smart aggregate (SA developed to utilize one Lead Zirconate Titanate (PZT transducer with marble protection is installed in the center location of the tendon duct as an actuator. Two PZT patches are bonded on the bottom and top surface of the tendon duct as the sensors. The analysis results show that the finite element analysis results are in good agreement with the experimental results, which demonstrates that the finite element analysis is feasible and reliable. For the top half of the specimen, not much stress wave could be detected before the full grouting level, except for negligible signals that may propagate through the walls of the tendon duct. When the tendon duct grouting is at 100%, the stress wave propagates to the top of the specimen, and the displacements are symmetric in both left-right and top-bottom directions before the stress waves reach the boundary. The proposed two-dimensional finite element model has the potential to be implemented to simulate the stress wave propagation principle for monitoring grouting compaction of the post-tensioning tendon

  10. Finite Element Analysis of Grouting Compactness Monitoring in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers.

    Science.gov (United States)

    Jiang, Tianyong; Zheng, Junbo; Huo, Linsheng; Song, Gangbing

    2017-09-29

    With the development of the post-tensioning technique, prestressed concrete structures have been widely used in civil engineering. To ensure the long-term effectiveness of the prestressed tendon, the grouting quality of the tendon duct is one of the important factors. However, it is still a challenge to monitor the grouting quality of post-tensioning tendon ducts, due to the invisibility of the grouting. The authors' previous work proposed a real-time method that employed a stress wave-based active sensing approach with piezoceramic transducers to monitor the grouting compactness of a Post-Tensioning Tendon Duct (PTTD). To further understand the piezoceramic induced stress wave propagation in the PTTD with different grouting levels, this paper develops a two-dimensional finite element model for monitoring the grouting compactness of the tendon duct with a piezoceramic transducer. A smart aggregate (SA) developed to utilize one Lead Zirconate Titanate (PZT) transducer with marble protection is installed in the center location of the tendon duct as an actuator. Two PZT patches are bonded on the bottom and top surface of the tendon duct as the sensors. The analysis results show that the finite element analysis results are in good agreement with the experimental results, which demonstrates that the finite element analysis is feasible and reliable. For the top half of the specimen, not much stress wave could be detected before the full grouting level, except for negligible signals that may propagate through the walls of the tendon duct. When the tendon duct grouting is at 100%, the stress wave propagates to the top of the specimen, and the displacements are symmetric in both left-right and top-bottom directions before the stress waves reach the boundary. The proposed two-dimensional finite element model has the potential to be implemented to simulate the stress wave propagation principle for monitoring grouting compaction of the post-tensioning tendon duct.

  11. IMPINGEMENT-SYNDROME OF PERONEUS BREVIS TENDON AFTER CALCANEAL FRACTURES (MORPHOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    N. S. Konovalchuk

    2017-01-01

    Full Text Available Background. One of the main causes of pain in patients with consequences of calcaneal fractures is the lateral impingement syndrome. This term means lateral displacement of outer calcaneal wall at the moment of fracture, narrowing of anatomical space under the lateral malleolus and compression of soft tissues in this region, including tendons of short and long peroneal muscles. This leads to chronic traumatization of tendons, alteration of their normal tracking and development of tendinitis and tenosynovitis. At this moment there are no articles in foreign or Russian literature describing how prolonged traumatization influences the internal structure of the tendons. The purpose of this study was to evaluate the morphological changes in structure of peroneus brevis tendon after different duration of compression between outer wall of calcaneus and the tip of the lateral malleolus in patients with calcaneal malunion.Materials and methods. Fifteen patients with calcaneal malunion and lateral impingement syndrome were treated operatively between 2016 and 2017. To confirm the lateral impingement syndrome, the authors performed clinical examination and AP x-rays of ankle joint. Two peroneus brevis tendon specimens were obtained intraoperatively in each of 15 patients: one specimen from compressed and one from non-compressed area. Obtained specimens were histologically examined according to standard protocol.Results. Microscopically all specimens showed separation of collagen bundles with loose connective tissue degeneration, increase of vascularization and inflammation. The degree of these changes differed according to the compression duration. This allowed us to analyze the dynamics of these changes.Conclusion. The morphological changes in structure of peroneus brevis tendon during the compression between outer wall of calcaneus and the tip of the lateral malleolus correspond with dynamics of common pathologic reactions. Early stages showed signs of

  12. IFSSH Flexor Tendon Committee report 2014: from the IFSSH Flexor Tendon Committee (Chairman: Jin Bo Tang).

    Science.gov (United States)

    Tang, Jin Bo; Chang, James; Elliot, David; Lalonde, Donald H; Sandow, Michael; Vögelin, Esther

    2014-01-01

    Hand surgeons continue to search for the best surgical flexor tendon repair and treatment of the tendon sheaths and pulleys, and they are attempting to establish postoperative regimens that fit diverse clinical needs. It is the purpose of this report to present the current views, methods, and suggestions of six senior hand surgeons from six different countries - all experienced in tendon repair and reconstruction. Although certainly there is common ground, the report presents provocative views and approaches. The report reflects an update in the views of the committee. We hope that it is helpful to surgeons and therapists in treating flexor tendon injuries.

  13. Effects of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex after hamstring harvesting for anterior cruciate ligament reconstruction. Evaluation using three-dimensional computed tomography

    International Nuclear Information System (INIS)

    Nakamae, Atsuo; Adachi, Nobuo; Nakasa, Tomoyuki; Nishimori, Makoto; Ochi, Mitsuo; Deie, Masataka

    2012-01-01

    It is desirable to maintain the morphology of the semitendinosus muscle-tendon complex after tendon harvesting for anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to evaluate the effect of knee immobilization on morphological changes in the semitendinosus muscle-tendon complex. In total, 39 patients who underwent ACL reconstruction with autologous semitendinosus tendons were included in this study. After surgery, the knee was immobilized for 3 days in 1 group of patients (group 1; 24 patients; control group) and for a longer period (10-14 days) in the other group (group 2; 15 patients). Three-dimensional computed tomography (3D CT) examination was performed at 6 and/or 12 months after the surgery for all patients. Morphological changes in the semitendinosus muscle-tendon complex (proximal shift of the semitendinosus muscle-tendon junction, width of the regenerated semitendinosus tendons, re-insertion sites of the regenerated tendons, and rate of semitendinosus tendon regeneration) were evaluated. Successful regeneration of the semitendinosus tendon was confirmed in all patients in group 2. In group 1, 3D CT showed that regeneration of the semitendinosus tendon was unsuccessful in 1 of the 24 patients. The average length of the proximal shift of the semitendinosus muscle-tendon junction was 7.3±2.5 cm in group 1 and 7.2±1.9 cm in group 2. There were no significant differences between the 2 groups with regard to the morphological changes in the semitendinosus muscle-tendon complex. This study showed that the structure of regenerated tendons could be clearly identified in 38 of 39 cases (97.4%) after ACL reconstruction. However, prolonged knee immobilization (10-14 days) could not prevent morphological changes in the semitendinosus muscle-tendon complex. (author)

  14. Combination of biochemical and mechanical cues for tendon tissue engineering.

    Science.gov (United States)

    Testa, Stefano; Costantini, Marco; Fornetti, Ersilia; Bernardini, Sergio; Trombetta, Marcella; Seliktar, Dror; Cannata, Stefano; Rainer, Alberto; Gargioli, Cesare

    2017-11-01

    Tendinopathies negatively affect the life quality of millions of people in occupational and athletic settings, as well as the general population. Tendon healing is a slow process, often with insufficient results to restore complete endurance and functionality of the tissue. Tissue engineering, using tendon progenitors, artificial matrices and bioreactors for mechanical stimulation, could be an important approach for treating rips, fraying and tissue rupture. In our work, C3H10T1/2 murine fibroblast cell line was exposed to a combination of stimuli: a biochemical stimulus provided by Transforming Growth Factor Beta (TGF-β) and Ascorbic Acid (AA); a three-dimensional environment represented by PEGylated-Fibrinogen (PEG-Fibrinogen) biomimetic matrix; and a mechanical induction exploiting a custom bioreactor applying uniaxial stretching. In vitro analyses by immunofluorescence and mechanical testing revealed that the proposed combined approach favours the organization of a three-dimensional tissue-like structure promoting a remarkable arrangement of the cells and the neo-extracellular matrix, reflecting into enhanced mechanical strength. The proposed method represents a novel approach for tendon tissue engineering, demonstrating how the combined effect of biochemical and mechanical stimuli ameliorates biological and mechanical properties of the artificial tissue compared to those obtained with single inducement. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  15. Terminology for Achilles tendon related disorders

    NARCIS (Netherlands)

    van Dijk, C. N.; van Sterkenburg, M. N.; Wiegerinck, J. I.; Karlsson, J.; Maffulli, N.

    2011-01-01

    The terminology of Achilles tendon pathology has become inconsistent and confusing throughout the years. For proper research, assessment and treatment, a uniform and clear terminology is necessary. A new terminology is proposed; the definitions hereof encompass the anatomic location, symptoms,

  16. Endoscopic Treatment of Intrasheath Peroneal Tendon Subluxation

    Directory of Open Access Journals (Sweden)

    Frederick Michels

    2013-01-01

    Full Text Available Intrasheath subluxation of the peroneal tendons within the peroneal groove is an uncommon problem. Open exploration combined with a peroneal groove-deepening procedure and retinacular reefing is the recommended treatment. This extensive lateral approach needs incision of the intact superior peroneal retinaculum and repair afterwards. We treated three patients with a painful intrasheath subluxation using an endoscopic approach. During this tendoscopy both tendons were inspected. The distal muscle fibers of the peroneus brevis tendon were resected in two patients. A partial tear was debrided in the third patient. All patients had a good result. No wound-healing problems or other complications occurred. Early return to work and sports was possible. An endoscopic approach was successful in treatment of an intrasheath subluxation of the peroneal tendons.

  17. Quadriceps Tendon Autograft Medial Patellofemoral Ligament Reconstruction.

    Science.gov (United States)

    Fink, Christian; Steensen, Robert; Gföller, Peter; Lawton, Robert

    2018-06-01

    Critically evaluate the published literature related to quadriceps tendon (QT) medial patellofemoral ligament (MPFL) reconstruction. Hamstring tendon (HT) MPFL reconstruction techniques have been shown to successfully restore patella stability, but complications including patella fracture are reported. Quadriceps tendon (QT) reconstruction techniques with an intact graft pedicle on the patella side have the advantage that patella bone tunnel drilling and fixation are no longer needed, reducing risk of patella fracture. Several QT MPFL reconstruction techniques, including minimally invasive surgical (MIS) approaches, have been published with promising clinical results and fewer complications than with HT techniques. Parallel laboratory studies have shown macroscopic anatomy and biomechanical properties of QT are more similar to native MPFL than hamstring (HS) HT, suggesting QT may more accurately restore native joint kinematics. Quadriceps tendon MPFL reconstruction, via both open and MIS techniques, have promising clinical results and offer valuable alternatives to HS grafts for primary and revision MPFL reconstruction in both children and adults.

  18. Jumper's Knee (Patellar Tendonitis) (For Parents)

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Jumper's Knee (Patellar Tendonitis) KidsHealth / For Parents / Jumper's Knee (Patellar ... prevent continued damage to the knee. How the Knee Works To understand how jumper's knee happens, it ...

  19. Experimental tests of pretensioned high strength tendons

    International Nuclear Information System (INIS)

    Hajutin, J.G.; Kriczewskij, A.Z.

    1977-01-01

    The tests carried out to estimate the losses of the prestressing force and the real bearing capacity of the parallel wire tendons and seven-wire strands are described. The practical experiences in tenden anchoring etc. are also received. (author)

  20. Investigations related to failure of prestressing tendons

    International Nuclear Information System (INIS)

    Boyadjiev, Z.

    1995-01-01

    Kozloduy NPP units 5 and 6 containment cladding shells are prestressed by the use of tendons 450 φ 5, made of high strength wires, class B-II. The prestressing force for each tendon is 10000 kN and the calculated breakdown force - 14000 kN. There are 96 tendons in the cylindrical part of the shell and 36 ones located in the containment dome. They are located in channel forming tubes of inner diameter of 200 mm, made of dense polyethylene. In order to assure biaxial prestressed condition, the prestressing tendons are located on screw shaped lines, both left and right, with declination to the horizon 35 degrees and 15 minutes. Each prestressing tendon initially forms a knee and following the bending at elevation + 10.80 m forms the other knee, in such a way, that its two ends are anchored in one and the same area-in a common or adjacent upper anchor boxes. The prestressing tendons in the containment dome are located in two perpendicular rows. Both ends of each tendon are anchored in a common fixing, the tendon being bent to the opposite side of the dome. During construction and operation of units 5 and 6, it was found, that the design prestressing force of 10000 kN can not be reached with some tendons, due to separate wires ruptures or due to the anchoring screw spent thread. The 1992 preliminary wires tests on a failed tendon found out deformation properties, different from the systematically obtained ones for the initial steel. Taking into consideration this fact, together with the IAEA regional project, concerning WWER-1000 seismic safety and items 4 and 6 of Kozloduy NPP Technical Council decisions of 10 June 1993, brought to delegation to the Research Construction Institute the performance of the technical analysis of the applied system for shell prestressing of containments of of units 5 and 6. The analysis comprises physical-mechanical and rheological properties of the high strength wires, used for containment shell prestressing and the over all technological

  1. Condition Assessment of PC Tendon Duct Filling by Elastic Wave Velocity Mapping

    Directory of Open Access Journals (Sweden)

    Kit Fook Liu

    2014-01-01

    Full Text Available Imaging techniques are high in demand for modern nondestructive evaluation of large-scale concrete structures. The travel-time tomography (TTT technique, which is based on the principle of mapping the change of propagation velocity of transient elastic waves in a measured object, has found increasing application for assessing in situ concrete structures. The primary aim of this technique is to detect defects that exist in a structure. The TTT technique can offer an effective means for assessing tendon duct filling of prestressed concrete (PC elements. This study is aimed at clarifying some of the issues pertaining to the reliability of the technique for this purpose, such as sensor arrangement, model, meshing, type of tendon sheath, thickness of sheath, and material type as well as the scale of inhomogeneity. The work involved 2D simulations of wave motions, signal processing to extract travel time of waves, and tomography reconstruction computation for velocity mapping of defect in tendon duct.

  2. MR imaging of the finger tendons: Normal anatomy and commonly encountered pathology

    International Nuclear Information System (INIS)

    Ragheb, Dina; Stanley, Anthony; Gentili, Amilcare; Hughes, Tudor; Chung, Christine B.

    2005-01-01

    MR imaging has emerged as a powerful tool in the evaluation of soft tissue structures such as the tendons of the hand and finger due to its excellent soft tissue contrast and multiplanar imaging capabilities. In the finger and hand, perhaps more than in any other location in the body, a detailed and intimate understanding of anatomy is crucial for lesion localization, directing clinical management and predicting long-term prognosis. These issues are of paramount importance to both the clinician and imager, both faced with the challenge of the complex anatomy and pathology associated with these delicate structures. The anatomy of the finger including intrinsic and extrinsic muscles, retinacular structures, and tendons will be discussed. The MR imaging features of common lesions of the tendons of the hand and finger will be reviewed

  3. Dynamic ultrasound of peroneal tendon instability.

    Science.gov (United States)

    Pesquer, Lionel; Guillo, Stéphane; Poussange, Nicolas; Pele, Eric; Meyer, Philippe; Dallaudière, Benjamin

    2016-07-01

    Ankle snapping may be caused by peroneal tendon instability. Anterior instability occurs after traumatic superior peroneal retinaculum injury, whereas peroneal tendon intrasheath subluxation is atraumatic. Whereas subluxation is mainly dynamic, ultrasound allows for the diagnosis and classification of peroneal instability because it allows for real-time exploration. The purpose of this review is to describe the anatomic and physiologic bases for peroneal instability and to heighten the role of dynamic ultrasound in the diagnosis of snapping.

  4. Visualization of the extra-articular portion of the long head of the biceps tendon during intra-articular shoulder arthroscopy.

    Science.gov (United States)

    Festa, Anthony; Allert, Jesse; Issa, Kimona; Tasto, James P; Myer, Jonathan J

    2014-11-01

    To quantify the amount of the extra-articular long head of the biceps tendon (LHBT) seen during intra-articular shoulder arthroscopy by pulling the tendon into the joint with a probe through an anterior portal while viewing through a standard posterior portal. Intra-articular shoulder arthroscopy was performed on 10 forequarter cadaveric specimens. The extra-articular portion of the LHBT was evaluated by pulling the tendon into the joint with an arthroscopic probe inserted through an anterior portal. The tendon was marked at the pulley insertion on the humerus with a vascular clip before and after the tendon was pulled into the joint. An open deltopectoral approach was performed, and the amount of extra-articular tendon visualized was calculated as an absolute amount and in relation to nearby anatomic structures. An additional 1.9 cm (range, 1.4 to 2.6 cm) of extra-articular LHBT was viewed by pulling the tendon into the joint with an arthroscopic probe through an anterior portal during shoulder arthroscopy. This represented 30.8% of the extra-articular portion of the tendon, 47.7% of tendon in the bicipital groove, and 76.3% of the tendon that lies under the area from the pulley insertion to the distal edge of the transverse humeral ligament. During intra-articular shoulder arthroscopy, the extra-articular portion of the LHBT is incompletely visualized by pulling the tendon into the joint with a probe placed through an anterior portal while viewing through a standard posterior portal. An additional extra-articular portion of the LHBT may be viewed by pulling the tendon into the joint with an arthroscopic probe during shoulder arthroscopy. Copyright © 2014 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  5. Optimization of human tendon tissue engineering: peracetic acid oxidation for enhanced reseeding of acellularized intrasynovial tendon.

    Science.gov (United States)

    Woon, Colin Y L; Pridgen, Brian C; Kraus, Armin; Bari, Sina; Pham, Hung; Chang, James

    2011-03-01

    Tissue engineering of human flexor tendons combines tendon scaffolds with recipient cells to create complete cell-tendon constructs. Allogenic acellularized human flexor tendon has been shown to be a useful natural scaffold. However, there is difficulty repopulating acellularized tendon with recipient cells, as cell penetration is restricted by a tightly woven tendon matrix. The authors evaluated peracetic acid treatment in optimizing intratendinous cell penetration. Cadaveric human flexor tendons were harvested, acellularized, and divided into experimental groups. These groups were treated with peracetic acid in varying concentrations (2%, 5%, and 10%) and for varying time periods (4 and 20 hours) to determine the optimal treatment protocol. Experimental tendons were analyzed for differences in tendon microarchitecture. Additional specimens were reseeded by incubation in a fibroblast cell suspension at 1 × 10(6) cells/ml. This group was then analyzed for reseeding efficacy. A final group underwent biomechanical studies for strength. The optimal treatment protocol comprising peracetic acid at 5% concentration for 4 hours produced increased scaffold porosity, improving cell penetration and migration. Treated scaffolds did not show reduced collagen or glycosaminoglycan content compared with controls (p = 0.37 and p = 0.65, respectively). Treated scaffolds were cytotoxic to neither attached cells nor the surrounding cell suspension. Treated scaffolds also did not show inferior ultimate tensile stress or elastic modulus compared with controls (p = 0.26 and p = 0.28, respectively). Peracetic acid treatment of acellularized tendon scaffolds increases matrix porosity, leading to greater reseeding. It may prove to be an important step in tissue engineering of human flexor tendon using natural scaffolds.

  6. Grasp Assist Device with Shared Tendon Actuator Assembly

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Bergelin, Bryan J. (Inventor); Bridgwater, Lyndon (Inventor)

    2015-01-01

    A grasp assist device includes a glove with first and second tendon-driven fingers, a tendon, and a sleeve with a shared tendon actuator assembly. Tendon ends are connected to the respective first and second fingers. The actuator assembly includes a drive assembly having a drive axis and a tendon hook. The tendon hook, which defines an arcuate surface slot, is linearly translatable along the drive axis via the drive assembly, e.g., a servo motor thereof. The flexible tendon is routed through the surface slot such that the surface slot divides the flexible tendon into two portions each terminating in a respective one of the first and second ends. The drive assembly may include a ball screw and nut. An end cap of the actuator assembly may define two channels through which the respective tendon portions pass. The servo motor may be positioned off-axis with respect to the drive axis.

  7. Periodic Safety Review of Tendon Pre-stress of Concrete Containment Building for a CA U-Type clear Power Plant

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Kwang Ho; Lim, Woo Sang [Korea Hydro and clear Power Co., Daejeon (Korea, Republic of)

    2009-10-15

    Generally, as the tendon pre-stress of concrete containment buildings at nuclear power plants decreases as time passes due to the concrete creep, concrete shrinkage and the relaxation of tendon strands, the tendon pre-stress must secure the structural integrity of these buildings by maintaining its value higher than that of the designed pre-stress during the overall service life of the nuclear power plants. Moreover, if necessary, the degree of tendon pre-stress must also guarantee the structural integrity of concrete containment buildings over their lifetimes. This paper evaluated the changes in the tendon pre-stress of a concrete containment building subject to time-limited aging as an item in a periodic safety review (PSR) of Wolsong unit 1, a CANDU-type nuclear power plant to ensure that the structural integrity can be maintained until the next PSR period after the designed lifetime.

  8. Improving the state of the art in FEM analysis of PCCVs with bonded and unbonded prestress tendons

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Christopher A., E-mail: cajone@sandia.gov [Sandia National Laboratories, PO Box 5800, MS 0744, Albuquerque, NM 87125-0744 (United States); Dameron, Robert, E-mail: rdameron@moffattnichol.com [Moffatt and Nichol, 1660 Hotel Cir N, San Diego, CA 92108 (United States); Sircar, Madhumita, E-mail: Madhumita.sircar@nrc.gov [U.S. Nuclear Regulatory Commission, Washington, DC 20555-0001 (United States)

    2015-12-15

    Highlights: • A novel method for FE modeling of bonded and unbonded tendons was developed. • Bonded and unbonded tendon models were compared for use in PCCVs. • For internal overpressurization, unbonded tendons perform slightly better. • Tendon slip and load redistribution are credited for the increased performance. - Abstract: In order to assess the structural performance of grouted prestressing systems in nuclear power containment vessels, a full containment vessel was modeled using the finite element program, ABAQUS. Both bonded (grouted) and unbonded (ungrouted) prestressing systems were modeled. Prior to simulation of grouting, both models were identical, with the prestressing stages modeled explicitly, and friction represented along the tendons. The results indicate higher peak stresses and strains in the bonded model since the tendon system is not permitted to slip and redistribute forces as the vessel deforms. Correspondingly, it is noted that the analysis predicts failure of the vessel at a lower internal pressure in the case of the bonded system. This work is an extension of a collaborative study of finite element analysis (FEA) of prestressed concrete containment vessels (PCCVs) sponsored by the United States Nuclear Regulatory Commission (USNRC) and the Atomic Energy Regulatory Board (AERB) of India. Particular emphasis was placed on advancing the state of the art in modeling tendons (Akin et al., 2013a; Heitman et al., 2014).

  9. Local trauma in human patellar tendon leads to widespread changes in the tendon gene expression

    DEFF Research Database (Denmark)

    Heinemeier, Katja Maria; Lorentzen, Marc P; Kildevang Jensen, Jacob

    2016-01-01

    Low cellular activity and slow tissue turnover in human tendon may prolong resolution of tendinopathy. This may be stimulated by moderate localized traumas such as needle penetrations, but whether this results in a widespread cellular response in tendons is unknown. In an initial hypothesis-gener...

  10. Histological Changes in the Proximal and Distal Tendon Stumps Following Transection of Achilles Tendon in the Rabbits.

    Science.gov (United States)

    Al-Qattan, Mohammad M; Mawlana, Ola Helmi; Mohammed Ahmed, Raeesa Abdel-Twab; Hawary, Khalid

    2016-05-01

    To determine tendon stump changes following unrepaired Achilles tendon lacerations in an animal model. An experimental study. King Saud University, Riyadh, Saudi Arabia, from October 2013 to January 2014. Arabbit model was developed and studied tendon retraction and histological changes in the proximal and distal stumps following transection of the Achilles tendon. Over a period of 12 weeks, retraction of the distal tendon stump was minimal (2 - 3 mm). In contrast, retraction of the proximal tendon stump peaked to reach 6 mm at 4 weeks post-injury and plateaued to reach 7 - 8 mm at the 12-week interval. Following complete transection of the Achilles tendon, tendon retraction correlated with the density of myofibroblast expression within the tendon stump. Further research is needed to investigate the pathophysiology of these findings.

  11. Histological Changes in the Proximal and Distal Tendon Stumps Following Transection of Achilles Tendon in the Rabbits

    International Nuclear Information System (INIS)

    Al-Qattan, M. M.; Hawary, K.; Mawlana, O. H.; Ahmed, R. A. M.

    2016-01-01

    Objective: To determine tendon stump changes following unrepaired Achilles tendon lacerations in an animal model. Study Design: An experimental study. Place and Duration of Study: King Saud University, Riyadh, Saudi Arabia, from October 2013 to January 2014. Methodology: Arabbit model was developed and studied tendon retraction and histological changes in the proximal and distal stumps following transection of the Achilles tendon. Result: Over a period of 12 weeks, retraction of the distal tendon stump was minimal (2 - 3 mm). In contrast, retraction of the proximal tendon stump peaked to reach 6 mm at 4 weeks post-injury and plateaued to reach 7 - 8 mm at the 12-week interval. Conclusion: Following complete transection of the Achilles tendon, tendon retraction correlated with the density of myofibroblast expression within the tendon stump. Further research is needed to investigate the pathophysiology of these findings. (author)

  12. Magnetic resonance imaging appearance of the flexor carpi radialis tendon after harvest in ligamentous reconstruction tendon interposition arthroplasty

    International Nuclear Information System (INIS)

    Beall, Douglas P.; Fish, Jon R.; Ritchie, Eric R.; Tran, Hoang N.; Ingari, John V.; Campbell, Scot E.; Grayson, David E.; Sanders, Timothy G.; Mundis, Gregory; Lehman, Thomas P.

    2006-01-01

    To determine whether the post-harvest magnetic resonance (MR) imaging appearance of flexor carpi radialis (FCR) tendons, harvested during ligamentous reconstruction tendon interposition (LRTI) of the thumb carpometacarpal (CMC) joint arthroplasty, is consistent with tendon regeneration. Operative reports and patient medical records for all patients undergoing LRTI arthroplasty between 1995 and 2003 at our institution were reviewed. MR images of the patients' forearms and wrists were obtained and interpreted by two musculoskeletal radiologists. Using the flexor carpi ulnaris (FCU) tendon as an internal standard, the extent of FCR tendon regeneration was expressed as a percentage by dividing the volume of regenerated FCR tendon by the volume of the FCU tendon. Fourteen patients who had the full thickness of the FCR tendon harvested and who were available for MR imaging were identified and included in the study. At least partial regeneration of the FCR tendon occurred in 11 of the 14 patients (79%). Of these, 2 patients (14%), demonstrated complete, or nearly complete regeneration. Partial regeneration of the FCR tendon was seen in 9 of the 14 patients (64%). In 3 patients (21%), there was no appreciable regeneration of the FCR tendon. Among patients who underwent full-thickness harvest of the FCR tendon for LRTI arthroplasty of the first CMC joint, the follow-up MR imaging appearance of the flexor carpi radialis tendon was consistent with tendon regeneration in 79% of those examined. (orig.)

  13. MR Imaging and US of the Wrist Tendons.

    Science.gov (United States)

    Plotkin, Benjamin; Sampath, Srihari C; Sampath, Srinath C; Motamedi, Kambiz

    2016-10-01

    The tendons of the wrist are commonly symptomatic. They can be injured, infected, or inflamed. Magnetic resonance imaging and ultrasonography are useful tools for evaluating the wrist. Pathologic conditions of the wrist tendons include de Quervain tenosynovitis, extensor carpi ulnaris tendinopathy, rheumatoid tenosynovitis, infectious synovitis, tendon tears, hydroxyapatite deposition disease, intersection syndrome, tenosynovial giant cell tumor, and fibroma of the tendon sheath. In this article, we review the normal appearance of the wrist tendons, discuss relevant anatomy, and give an overview of common pathologic conditions affecting the wrist tendons. Online supplemental material is available for this article. © RSNA, 2016.

  14. Mechanical properties of the human Achilles tendon, in vivo

    DEFF Research Database (Denmark)

    Kongsgaard, M; Nielsen, C H; Hegnsvad, S

    2011-01-01

    Ultrasonography has been widely applied for in vivo measurements of tendon mechanical properties. Assessments of human Achilles tendon mechanical properties have received great interest. Achilles tendon injuries predominantly occur in the tendon region between the Achilles-soleus myotendinous...... junction and Achilles-calcaneus osteotendinous junction i.e. in the free Achilles tendon. However, there has been no adequate ultrasound based method for quantifying the mechanical properties of the free human Achilles tendon. This study aimed to: 1) examine the mechanical properties of the free human...

  15. Optimal arm posture control and tendon traction forces of a coupled tendon-driven manipulator

    International Nuclear Information System (INIS)

    Ma, Shugen

    1997-01-01

    In this study, the optimum arm posture of a coupled tendon-driven multijoint manipulator arm (or CT Arm) at maximum payload output was derived and the corresponding tendon traction forces were also analyzed, during management of a heavy payload by the manipulator in a gravity environment. The CT Arm is special tendon traction transmission mechanism in which a pair of tendons used to drive a joint is pulled from base actuators via pulleys mounted on the base-side joints. This mechanism enables optimal utilization of the coupled drive function of tendon traction forces and thus enables the lightweight manipulator to exhibit large payload capability. The properties of the CT Arm mechanism are elucidated by the proposed optimal posture control scheme. Computer simulation was also executed to verify the validity of the proposed control scheme. (author)

  16. Highly Unusual Tendon Abnormality: Spontaneous Rupture of the Distal Iliopsoas Tendon

    Directory of Open Access Journals (Sweden)

    Gokcen Coban

    2014-06-01

    Full Text Available Iliopsoas tendon injuries are not common and usually occur due to avulsion of the iliopsoas tendon with detachment of the lesser trochanter, secondary to an athletic injury or trauma. In the absence of a trauma, avulsion of the lesser trochanter in an adult is regarded as a sign of metastatic disease until proven otherwise. Complete iliopsoas tendon tears have thus far only been described in elderly women, and without trauma or an underlying systemic disease, a hormonal basis may be a reason for the gender differences. In this article, we present an 87-year-old woman with spontaneous rupture of the left distal iliopsoas tendon unassociated with fracture of the lesser trochanter and in the absence of a recent trauma history. This elderly patient presented with acute groin pain and normal plain radiographs. Magnetic resonance imaging must be kept in mind as a modality of choice for identifying iliopsoas tendon abnormalities.

  17. Feasibility Verification of Mountable PZT-Interface for Impedance Monitoring in Tendon-Anchorage

    Directory of Open Access Journals (Sweden)

    Thanh-Canh Huynh

    2015-01-01

    Full Text Available This study has been motivated to numerically evaluate the performance of the mountable PZT-interface for impedance monitoring in tendon-anchorage. Firstly, electromechanical impedance monitoring and feature classification methods are outlined. Secondly, a structural model of tendon-anchorage subsystem with mountable PZT-interface is designed for impedance monitoring. Finally, the feasibility of the mountable PZT-interface is numerically examined. A finite element (FE model is designed for the lab-scaled tendon-anchorage. The FE model of the PZT-interface is tuned as its impedance signatures meet the experimental test results at the same frequency ranges and also with identical patterns. Equivalent model properties of the FE model corresponding to prestress forces inflicted on the lab-tested structure are identified from the fine-tuning practice.

  18. Lower Robotic Arm Assembly Having a Plurality of Tendon Driven Digits

    Science.gov (United States)

    Guo, Raymond (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Radford, Nicolaus A. (Inventor)

    2016-01-01

    A lower robotic arm includes a base structure, a plurality of digits, and a plurality of tendons. The digits each include first, second, third, and fourth phalanges. Each digit is operatively attached to the base structure at the respective first phalange. A first joint operatively connects the first and second phalange to define a first axis, a second operatively connects the second and third phalange to define a second axis, and a third joint operatively connects the third and fourth phalange to define a third axis, such that the phalanges are selectively rotatable relative to the adjacent phalange, about the respective axis. The tendons are operatively connected to a respective one of the fourth phalanges. Each tendon selectively applies a first torque to the respective fourth phalange to urge the respective phalanges to rotate in a first direction about the respective axes.

  19. Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

    Energy Technology Data Exchange (ETDEWEB)

    MacMahon, P.J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland)]. E-mail: petermacmahon@yahoo.com; Taylor, D.H. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Duke, D. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Brennan, D.D. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); O' Brien, J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Eustace, S.J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland)

    2007-06-15

    Aim: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. Materials and methods: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. Results: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p < 0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p < 0.05). There were no significant differences in coraco-humeral distances between the groups. Conclusion: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.

  20. Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

    International Nuclear Information System (INIS)

    MacMahon, P.J.; Taylor, D.H.; Duke, D.; Brennan, D.D.; O'Brien, J.; Eustace, S.J.

    2007-01-01

    Aim: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. Materials and methods: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. Results: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p < 0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p < 0.05). There were no significant differences in coraco-humeral distances between the groups. Conclusion: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed

  1. Quantitative Analysis of Patellar Tendon Abnormality in Asymptomatic Professional “Pallapugno” Players: A Texture-Based Ultrasound Approach

    Directory of Open Access Journals (Sweden)

    Kristen M. Meiburger

    2018-04-01

    Full Text Available Abnormalities in B-mode ultrasound images of the patellar tendon often take place in asymptomatic athletes but it is still not clear if these modifications forego or can predict the development of tendinopathy. Subclinical tendinopathy can be arbitrarily defined as either (1 the presence of light structural changes in B-mode ultrasound images in association with mild neovascularization (determined with Power Doppler images or (2 the presence of moderate/severe structural changes with or without neovascularization. Up to now, the structural changes and neovascularization of the tendon are evaluated qualitatively by visual inspection of ultrasound images. The aim of this study is to investigate the capability of a quantitative texture-based approach to determine tendon abnormality of “pallapugno” players. B-mode ultrasound images of the patellar tendon were acquired in 14 players and quantitative texture parameters were calculated within a Region of Interest (ROI of both the non-dominant and the dominant tendon. A total of 90 features were calculated for each ROI, including 6 first-order descriptors, 24 Haralick features, and 60 higher-order spectra and entropy features. These features on the dominant and non-dominant side were used to perform a multivariate linear regression analysis (MANOVA and our results show that the descriptors can be effectively used to determine tendon abnormality and, more importantly, the occurrence of subclinical tendinopathy.

  2. No Telescoping Effect with Dual Tendon Vibration.

    Directory of Open Access Journals (Sweden)

    Valeria Bellan

    Full Text Available The tendon vibration illusion has been extensively used to manipulate the perceived position of one's own body part. However, findings from previous research do not seem conclusive sregarding the perceptual effect of the concurrent stimulation of both agonist and antagonist tendons over one joint. On the basis of recent data, it has been suggested that this paired stimulation generates an inconsistent signal about the limb position, which leads to a perceived shrinkage of the limb. However, this interesting effect has never been replicated. The aim of the present study was to clarify the effect of a simultaneous and equal vibration of the biceps and triceps tendons on the perceived location of the hand. Experiment 1 replicated and extended the previous findings. We compared a dual tendon stimulation condition with single tendon stimulation conditions and with a control condition (no vibration on both 'upward-downward' and 'towards-away from the elbow' planes. Our results show a mislocalisation towards the elbow of the position of the vibrated arm during dual vibration, in line with previous results; however, this did not clarify whether the effect was due to arm representation contraction (i.e., a 'telescoping' effect. Therefore, in Experiment 2 we investigated explicitly and implicitly the perceived arm length during the same conditions. Our results clearly suggest that in all the vibration conditions there was a mislocalisation of the entire arm (including the elbow, but no evidence of a contraction of the perceived arm length.

  3. Postoperative US of leg tendon reconstruction

    International Nuclear Information System (INIS)

    Draghi, F.; Calliada, F.; Fulle, I.; Madonia, L.; Bottinelli, O.; Campani, R.

    1999-01-01

    The role of ultrasound (US) in the postoperative assessment of tendon reconstruction is not clearly defined and there is non systematic arrangement of US patterns. The authors examined 34 patients submitted to surgery or conservative treatment for total/partial tear or musculotendinous detachment of patellar or Achilles tendon in the last 5 years. All patients underwent physical and US examinations. The surgical tendon exhibited the same US patterns in 23/28 patients: it was markedly enlarged (three-/fourfold the normal diameter) and more rounded, with inhomogeneous and hypoechoic appearance not only at the tear/surgical site but also above and below it, for some cm. Small hyperechoic images, mainly dots, were seen in 19 cases, which were referable to small calcifications and stitches. More and larger calcifications were found in 8 patients, where they were associated with anechoic degeneration areas. Color Doppler US showed moderate or strong hypervascularization around the tear in the first months post injury. US patterns did not correlate with physical findings, but color Doppler patterns did. In 6 cases of musculotendinous detachment submitted to conservative treatment, US showed enlargement and hypoechogenicity in the injury site only, with no involvement of the remaining tendon. US was also used to time and guide drainage of perilesional hematomas, which were often quite large. US is the method of choice in the postoperative follow-up of tendon tears and musculotendinous detachments because it shows abnormal signs which are missed at clinics and provides additional information needed for treatment planning [it

  4. management of open achilles tendon injury: primary repair and early ...

    African Journals Online (AJOL)

    is attributable to increase in both competitive and recreational sports. In most of the literature written on Achilles tendon injuries there were rarely any information about open Achilles tendon ... The most common aetiology was motorbike spoke.

  5. Robot Arm with Tendon Connector Plate and Linear Actuator

    Science.gov (United States)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Bridgwater, Lyndon (Inventor); Nguyen, Vienny (Inventor); Millerman, Alexander (Inventor)

    2014-01-01

    A robotic system includes a tendon-driven end effector, a linear actuator, a flexible tendon, and a plate assembly. The linear actuator assembly has a servo motor and a drive mechanism, the latter of which translates linearly with respect to a drive axis of the servo motor in response to output torque from the servo motor. The tendon connects to the end effector and drive mechanism. The plate assembly is disposed between the linear actuator assembly and the tendon-driven end effector and includes first and second plates. The first plate has a first side that defines a boss with a center opening. The second plate defines an accurate through-slot having tendon guide channels. The first plate defines a through passage for the tendon between the center opening and a second side of the first plate. A looped end of the flexible tendon is received within the tendon guide channels.

  6. Correspondence of high-frequency ultrasound and histomorphometry of healing rabbit Achilles tendon tissue.

    Science.gov (United States)

    Buschmann, Johanna; Puippe, Gilbert; Bürgisser, Gabriella Meier; Bonavoglia, Eliana; Giovanoli, Pietro; Calcagni, Maurizio

    2014-04-01

    Static and dynamic high-frequency ultrasound of healing rabbit Achilles tendons were set in relationship to histomorphometric analyses at three and six weeks post-surgery. Twelve New Zealand White rabbits received a clean-cut Achilles tendon laceration (the medial and lateral Musculus gastrocnemius) and were repaired with a four-strand Becker suture. Six rabbits got additionally a tight polyester urethane tube at the repair site in order to vary the adhesion extent. Tendons were analysed by static and dynamic ultrasound (control: healthy contralateral legs). The ultrasound outcome was corresponded to the tendon shape, tenocyte and tenoblast density, tenocyte and tenoblast nuclei width, collagen fibre orientation and adhesion extent. The spindle-like morphology of healing tendons (ultrasound) was confirmed by the swollen epitenon (histology). Prediction of adhesion formation by dynamic ultrasound assessment was confirmed by histology (contact region to surrounding tissue). Hyperechogenic areas corresponded to acellular zones with aligned fibres and hypoechogenic zones to not yet oriented fibres and to cell-rich areas. These findings add new in-depth structural knowledge to the established non-invasive analytical tool, ultrasound.

  7. Multiscale mechanical integrity of human supraspinatus tendon in shear after elastin depletion.

    Science.gov (United States)

    Fang, Fei; Lake, Spencer P

    2016-10-01

    Human supraspinatus tendon (SST) exhibits region-specific nonlinear mechanical properties under tension, which have been attributed to its complex multiaxial physiological loading environment. However, the mechanical response and underlying multiscale mechanism regulating SST behavior under other loading scenarios are poorly understood. Furthermore, little is known about the contribution of elastin to tendon mechanics. We hypothesized that (1) SST exhibits region-specific shear mechanical properties, (2) fiber sliding is the predominant mode of local matrix deformation in SST in shear, and (3) elastin helps maintain SST mechanical integrity by facilitating force transfer among collagen fibers. Through the use of biomechanical testing and multiphoton microscopy, we measured the multiscale mechanical behavior of human SST in shear before and after elastase treatment. Three distinct SST regions showed similar stresses and microscale deformation. Collagen fiber reorganization and sliding were physical mechanisms observed as the SST response to shear loading. Measures of microscale deformation were highly variable, likely due to a high degree of extracellular matrix heterogeneity. After elastase treatment, tendon exhibited significantly decreased stresses under shear loading, particularly at low strains. These results show that elastin contributes to tendon mechanics in shear, further complementing our understanding of multiscale tendon structure-function relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Tenomodulin is Required for Tendon Endurance Running and Collagen I Fibril Adaptation to Mechanical Load

    Directory of Open Access Journals (Sweden)

    Sarah Dex

    2017-06-01

    Full Text Available Tendons are dense connective tissues that attach muscles to bone with an indispensable role in locomotion because of their intrinsic properties of storing and releasing muscle- generated elastic energy. Tenomodulin (Tnmd is a well-accepted gene marker for the mature tendon/ligament lineage and its loss-of -function in mice leads to a phenotype with distinct signs of premature aging on tissue and stem/progenitor cell levels. Based on these findings, we hypothesized that Tnmd might be an important factor in the functional performance of tendons. Firstly, we revealed that Tnmd is a mechanosensitive gene and that the C-terminus of the protein co-localize with collagen I-type fibers in the extracellular matrix. Secondly, using an endurance training protocol, we compared Tnmd knockout mice with wild types and showed that Tnmd deficiency leads to significantly inferior running performance that further worsens with training. In these mice, endurance running was hindered due to abnormal response of collagen I cross-linking and proteoglycan genes leading to an inadequate collagen I fiber thickness and elasticity. In sum, our study demonstrates that Tnmd is required for proper tendon tissue adaptation to endurance running and aids in better understanding of the structural-functional relationships of tendon tissues.

  9. [Three-dimensional parallel collagen scaffold promotes tendon extracellular matrix formation].

    Science.gov (United States)

    Zheng, Zefeng; Shen, Weiliang; Le, Huihui; Dai, Xuesong; Ouyang, Hongwei; Chen, Weishan

    2016-03-01

    To investigate the effects of three-dimensional parallel collagen scaffold on the cell shape, arrangement and extracellular matrix formation of tendon stem cells. Parallel collagen scaffold was fabricated by unidirectional freezing technique, while random collagen scaffold was fabricated by freeze-drying technique. The effects of two scaffolds on cell shape and extracellular matrix formation were investigated in vitro by seeding tendon stem/progenitor cells and in vivo by ectopic implantation. Parallel and random collagen scaffolds were produced successfully. Parallel collagen scaffold was more akin to tendon than random collagen scaffold. Tendon stem/progenitor cells were spindle-shaped and unified orientated in parallel collagen scaffold, while cells on random collagen scaffold had disorder orientation. Two weeks after ectopic implantation, cells had nearly the same orientation with the collagen substance. In parallel collagen scaffold, cells had parallel arrangement, and more spindly cells were observed. By contrast, cells in random collagen scaffold were disorder. Parallel collagen scaffold can induce cells to be in spindly and parallel arrangement, and promote parallel extracellular matrix formation; while random collagen scaffold can induce cells in random arrangement. The results indicate that parallel collagen scaffold is an ideal structure to promote tendon repairing.

  10. The Puller-Follower Control of Compliant and Noncompliant Antagonistic Tendon Drives in Robotic Systems

    Directory of Open Access Journals (Sweden)

    Veljko Potkonjak

    2011-11-01

    Full Text Available This paper proposes a new control strategy for noncompliant and compliant antagonistic tendon drives. It is applied to a succession of increasingly complex single‐joint systems, starting with a linear and noncompliant system and ending with a revolute, nonlinearly tendon coupled and compliant system. The last configuration mimics the typical human joint structure, used as a model for certain joints of the anthropomimetic robot ECCEROBOT. The control strategy is based on a biologically inspired puller‐ follower concept, which distinguishes the roles of the agonist and antagonist motors. One actuator, the puller, is considered as being primarily responsible for the motion, while the follower prevents its tendon from becoming slack by maintaining its tendon force at some non‐zero level. Certain movements require switching actuator roles; adaptive co‐contraction is used to prevent tendons slackening, while maintaining energetic efficiency. The single‐joint control strategy is then evaluated in a multi‐ joint system. Dealing with the gravitational and dynamic effects arising from the coupling in a multi‐joint system, a robust control design has to be applied with on‐line gravity compensation. Finally, an experiment corresponding to object grasping is presented to show the controller

  11. The Puller-Follower Control of Compliant and Noncompliant Antagonistic Tendon Drives in Robotic Systems

    Directory of Open Access Journals (Sweden)

    Veljko Potkonjak

    2011-11-01

    Full Text Available This paper proposes a new control strategy for noncompliant and compliant antagonistic tendon drives. It is applied to a succession of increasingly complex single-joint systems, starting with a linear and noncompliant system and ending with a revolute, nonlinearly tendon coupled and compliant system. The last configuration mimics the typical human joint structure, used as a model for certain joints of the anthropomimetic robot ECCEROBOT. The control strategy is based on a biologically inspired puller-follower concept, which distinguishes the roles of the agonist and antagonist motors. One actuator, the puller, is considered as being primarily responsible for the motion, while the follower prevents its tendon from becoming slack by maintaining its tendon force at some non-zero level. Certain movements require switching actuator roles; adaptive co-contraction is used to prevent tendons slackening, while maintaining energetic efficiency. The single-joint control strategy is then evaluated in a multi-joint system. Dealing with the gravitational and dynamic effects arising from the coupling in a multi-joint system, a robust control design has to be applied with on-line gravity compensation. Finally, an experiment corresponding to object grasping is presented to show the controller's robustness to external disturbances.

  12. Partial tear of the quadriceps tendon in a child

    International Nuclear Information System (INIS)

    Khanna, Geetika; El-Khoury, George

    2008-01-01

    We present a case of partial rupture of the quadriceps tendon in an 8-year-old girl. This is one of the youngest patients reported with a quadriceps tendon rupture, an entity seen predominantly in middle-aged people. The strength of the muscle tendon unit in a child makes tendon injuries extremely unusual as compared to apophyseal avulsions. The MR imaging findings of this unusual pediatric injury are illustrated. (orig.)

  13. Calcaneal tendon: imaging findings; Tendao calcaneo: avaliacao por imagem

    Energy Technology Data Exchange (ETDEWEB)

    Montandon, Cristiano; Fonseca, Cristiano Rezio; Montandon Junior, Marcelo Eustaquio [Colegio Brasileiro de Radiologia e Diagnostico por Imagem, Sao Paulo, SP (Brazil)]. E-mail: crismontandon@hotmail.com; Lobo, Leonardo Valadares; Ribeiro, Flavia Aparecida de Souza; Teixeira, Kim-Ir-Sen Santos [Goias Univ., Goiania, GO (Brazil). Hospital de Clinicas. Dept. de Diagnostico por Imagem e Anatomia Patologica

    2003-12-01

    We reviewed the radiological and clinical features of 23 patients with calcaneal tendon diseases, who were submitted to ultrasound or magnetic resonance imaging. The objective of this study was to characterize the lesions for a precise diagnosis of calcaneal tendon injuries. A wide range of calcaneal tendon diseases include degenerative lesions, inflammation of the peritendinous tissue such as peritendinitis and bursitis, and rupture. Imaging methods are essential in the diagnosis, treatment and follow-up of calcaneal tendon diseases. (author)

  14. MRI in flexor tendon rupture after collagenase injection

    International Nuclear Information System (INIS)

    Khurana, Shruti; Wadhwa, Vibhor; Chhabra, Avneesh; Amirlak, Bardia

    2017-01-01

    Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture. (orig.)

  15. MRI in flexor tendon rupture after collagenase injection

    Energy Technology Data Exchange (ETDEWEB)

    Khurana, Shruti [Lady Hardinge Medical College, New Delhi (India); Wadhwa, Vibhor [University of Arkansas for Medical Sciences, Little Rock, AR (United States); Chhabra, Avneesh [UT Southwestern Medical Center, Dallas, TX (United States); Johns Hopkins University, Baltimore, MD (United States); Amirlak, Bardia [UT Southwestern Medical Center, Dallas, TX (United States)

    2017-02-15

    Flexor tendon rupture is an unusual complication following collagenase injection to relieve contractures. These patients require a close follow-up and in the event of tendon rupture, a decision has to be made whether to repair the tendon or manage the complication conservatively. The authors report the utility of MRI in the prognostication and management of a patient with Dupuytren's contracture, who underwent collagenase injection and subsequently developed flexor digitorum profundus tendon rupture. (orig.)

  16. PERONEAL TENDON LESIONS IN ATHLETES (REVIEW

    Directory of Open Access Journals (Sweden)

    E. E. Achkasov

    2016-01-01

    Full Text Available The authors analyzed scientific literature in respect of various issues in treatment of athletes with peroneal muscles lesions starting from 1987 till 2016. Key search and publications selection was made in PubMed and russian national electronic scientific library eLIBRARY. Peroneal tendons pathology is not the major but the underestimated cause of pain in lateral and hindfoot as well as of foot dysfunction which is difficult to distinguish from lesions of lateral ligaments of the ankle joint. Untreated lesions of peroneal tendons can result in chronic ankle pain and significant functional disorders. The purpose of the present paper is to improve the current comprehension of anatomy, to identify factors contributing to pathology, to perform diagnostic evaluation of peroneal tendons and to review current treatment options of such lesions.

  17. Triple Achilles Tendon Rupture: Case Report.

    Science.gov (United States)

    Saxena, Amol; Hofer, Deann

    We present a case report with 1-year follow-up data of a 57-year-old male soccer referee who had sustained an acute triple Achilles tendon rupture injury during a game. His triple Achilles tendon rupture consisted of a rupture of the proximal watershed region, a rupture of the main body (mid-watershed area), and an avulsion-type rupture of insertional calcific tendinosis. The patient was treated surgically with primary repair of the tendon, including tenodesis with anchors. Postoperative treatment included non-weightbearing for 4 weeks and protected weightbearing until 10 weeks postoperative, followed by formal physical therapy, which incorporated an "antigravity" treadmill. The patient was able to return to full activity after 26 weeks, including running and refereeing, without limitations. Copyright © 2017 The American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Lateral force transmission between human tendon fascicles

    DEFF Research Database (Denmark)

    Haraldsson, Bjarki T; Aagaard, Per; Qvortrup, Klaus

    2008-01-01

    Whether adjacent collagen fascicles transmit force in parallel is unknown. The purpose of the present study was to examine the magnitude of lateral force transmission between adjacent collagen fascicles from the human patellar and Achilles tendon. From each sample two adjacent strands of fascicles...... was transversally cut while the other fascicle and the fascicular membrane were kept intact. Cycle 3: both fascicles were cut in opposite ends while the fascicular membrane was left intact. A decline in peak force of 45% and 55% from cycle 1 to cycle 2, and 93% and 92% from cycle 2 to cycle 3 was observed...... in the patellar and Achilles tendon fascicles, respectively. A decline in stiffness of 39% and 60% from cycle 1 to cycle 2, and of 93% and 100% from cycle 2 to cycle 3 was observed in the patellar and Achilles tendon fascicles, respectively. The present data demonstrate that lateral force transmission between...

  19. Reinforced concrete T-beams externally prestressed with unbonded carbon fiber-reinforced polymer tendons

    DEFF Research Database (Denmark)

    Bennitz, Anders; Nilimaa, Jonny; Täljsten, Björn

    2012-01-01

    force, and the presence of a deviator were investigated. The results were compared to those observed with analogous beams prestressed with steel tendons, common beam theory, and predictions made using an analytical model adapted from the literature. It was found that steel and CFRP tendons had very...... similar effects on the structural behavior of the strengthened beams; the minor differences that were observed are attributed to the difference between the modulus of elasticity of the CFRP and the steel used in the tests. The models predicted the beams' load-bearing behavior accurately but were less...

  20. Unbonded prestressing tendons and their role in the construction of slender elements of buildings

    Science.gov (United States)

    Mieszczak, M.

    2018-03-01

    Steel unbonded tendons have been introduced in Europe for construction prestressing many years later than in the USA, Honkong, Singapore or Australia. In Poland, they appeared in the early 1990s. Despite their short application, in the last decade, the Institute of Materials and Building Constructions of the Cracow University of Technology in cooperation with the TCE Structural Design & Consulting company has developed and implemented several interesting and unique designs of building components, using the advantages of this type of prestressing. In the author’s work, apart from the short description of these tendons, several selected (own and foreign) projects of unique character have been presented.

  1. Development of high shrinkage polyethylene terephthalate (PET) shape memory polymer tendons for concrete crack closure

    Science.gov (United States)

    Teall, Oliver; Pilegis, Martins; Sweeney, John; Gough, Tim; Thompson, Glen; Jefferson, Anthony; Lark, Robert; Gardner, Diane

    2017-04-01

    The shrinkage force exerted by restrained shape memory polymers (SMPs) can potentially be used to close cracks in structural concrete. This paper describes the physical processing and experimental work undertaken to develop high shrinkage die-drawn polyethylene terephthalate (PET) SMP tendons for use within a crack closure system. The extrusion and die-drawing procedure used to manufacture a series of PET tendon samples is described. The results from a set of restrained shrinkage tests, undertaken at differing activation temperatures, are also presented along with the mechanical properties of the most promising samples. The stress developed within the tendons is found to be related to the activation temperature, the cross-sectional area and to the draw rate used during manufacture. Comparisons with commercially-available PET strip samples used in previous research are made, demonstrating an increase in restrained shrinkage stress by a factor of two for manufactured PET filament samples.

  2. Bilateral spontaneous rupture of flexor digitorum profundus tendons.

    LENUS (Irish Health Repository)

    O'Sullivan, S T

    2012-02-03

    Spontaneous tendon rupture is an unusual condition usually associated with underlying disease processes such as rheumatoid arthritis, chronic renal failure or bony abnormalities of the hand. We report a case of spontaneous, non-concurrent bilateral rupture of flexor profundus tendons in an otherwise healthy individual. Treatment was successful and consisted of a two-stage reconstruction of the ruptured tendon.

  3. Ultrasound of the elbow with emphasis on detailed assessment of ligaments, tendons, and nerves

    International Nuclear Information System (INIS)

    De Maeseneer, Michel; Brigido, Monica Kalume; Antic, Marijana; Lenchik, Leon; Milants, Annemieke; Vereecke, Evie; Jager, Tjeerd; Shahabpour, Maryam

    2015-01-01

    Highlights: •Medial and lateral tendons: the different muscles forming these tendons can be followed up to the insertion. The imaging anatomy is reviewed. •Medial and lateral ligaments: the anatomy is complex and specialized imaging planes and arm positions are necessary for accurate assessment. •Biceps tendon: the anatomy of the distal biceps and lacertus fibrosus are discussed and illustrated with cadaveric correlation. •US imaging of the nerves about the elbow and visualization of the possible compression points is discussed. -- Abstract: The high resolution and dynamic capability of ultrasound make it an excellent tool for assessment of superficial structures. The ligaments, tendons, and nerves about the elbow can be fully evaluated with ultrasound. The medial collateral ligament consists of an anterior and posterior band that can easily be identified. The lateral ligament complex consists of the radial collateral ligament, ulnar insertion of the annular ligament, and lateral ulnar collateral ligament, easily identified with specialized probe positioning. The lateral ulnar collateral ligament can best be seen in the cobra position. On ultrasound medial elbow tendons can be followed nearly up to their common insertion. The pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis can be identified. The laterally located brachioradialis and extensor carpi radialis longus insert on the supracondylar ridge. The other lateral tendons can be followed up to their common insertion on the lateral epicondyle. The extensor digitorum, extensor carpi radialis brevis, extensor digiti minimi, and extensor carpi ulnaris can be differentiated. The distal biceps tendon is commonly bifid. For a complete assessment of the distal biceps tendon specialized views are necessary. These include an anterior axial approach, medial and lateral approach, and cobra position. In the cubital tunnel the ulnar nerve is covered by the ligament of Osborne

  4. Ultrasound of the elbow with emphasis on detailed assessment of ligaments, tendons, and nerves

    Energy Technology Data Exchange (ETDEWEB)

    De Maeseneer, Michel, E-mail: Michel.demaeseneer@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Brigido, Monica Kalume, E-mail: Mbrigido@med.umich.edu [Department of Radiology, University of Michigan, Ann Arbor, MI (United States); Antic, Marijana, E-mail: Misscroa@gmail.com [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Lenchik, Leon, E-mail: Llenchik@wakehealth.edu [Department of Radiology, Wake Forest University, Winston-Salem, NC (United States); Milants, Annemieke, E-mail: Annemieke.Milants@gmail.com [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium); Vereecke, Evie, E-mail: Evie.Vereecke@kuleuven-kulak.be [Department of Anatomy, KULAK, Katholieke Universiteit Leuven, Campus Kortrijk, Kortrijk (Belgium); Jager, Tjeerd [Aalsters Stedelijk Ziekenhuis, Aalst (Belgium); Shahabpour, Maryam, E-mail: Maryam.Shahabpour@uzbrussel.be [Department of Radiology, Universitair Ziekenhuis Brussel, Brussels (Belgium)

    2015-04-15

    Highlights: •Medial and lateral tendons: the different muscles forming these tendons can be followed up to the insertion. The imaging anatomy is reviewed. •Medial and lateral ligaments: the anatomy is complex and specialized imaging planes and arm positions are necessary for accurate assessment. •Biceps tendon: the anatomy of the distal biceps and lacertus fibrosus are discussed and illustrated with cadaveric correlation. •US imaging of the nerves about the elbow and visualization of the possible compression points is discussed. -- Abstract: The high resolution and dynamic capability of ultrasound make it an excellent tool for assessment of superficial structures. The ligaments, tendons, and nerves about the elbow can be fully evaluated with ultrasound. The medial collateral ligament consists of an anterior and posterior band that can easily be identified. The lateral ligament complex consists of the radial collateral ligament, ulnar insertion of the annular ligament, and lateral ulnar collateral ligament, easily identified with specialized probe positioning. The lateral ulnar collateral ligament can best be seen in the cobra position. On ultrasound medial elbow tendons can be followed nearly up to their common insertion. The pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis can be identified. The laterally located brachioradialis and extensor carpi radialis longus insert on the supracondylar ridge. The other lateral tendons can be followed up to their common insertion on the lateral epicondyle. The extensor digitorum, extensor carpi radialis brevis, extensor digiti minimi, and extensor carpi ulnaris can be differentiated. The distal biceps tendon is commonly bifid. For a complete assessment of the distal biceps tendon specialized views are necessary. These include an anterior axial approach, medial and lateral approach, and cobra position. In the cubital tunnel the ulnar nerve is covered by the ligament of Osborne

  5. Ultrasound diagnostics of muscle and tendon injuries

    Directory of Open Access Journals (Sweden)

    Stević Ruža

    2009-01-01

    Full Text Available Introduction. Sonography is a useful technique for the investigation of a number of musculoskeletal disorders. The most common indication for ultrasonography of muscles and tendons is the diagnosis of traumatic lesions, distinguishing them from other disorders and follow-up of healing process. Objective. The purpose of this paper is to show the importance of ultrasound in the diagnosis of muscle and tendon injuries. Methods. The study included 170 patients (148 male and 22 female, mean age 29.6 years (range 14-60 years. All examinations were performed by linear transducer of 7.5-10 MHz, with longitudinal and transverse scanning. Ultrasound examination followed physical examination. Results. Traumatic lesions of muscles were diagnosed in 113 patients (66.7% and tendon injuries in 57 cases (33.2%. The muscle changes detected by ultrasonography were the following: 70 (61.9% partial and two (1.76% complete ruptures, 22 (19.46% haematoma, 9 (7.96% strains grade I, 4 fibroses and 4 ossifying myositis 4 (3.5%, respectively. Complications of muscle injuries were diagnosed in two cases, a muscular hernia and an arteriovenous fistula. Among tendon injuries, 21 (33.8% ruptures and 36 (66.1% tendinitis were diagnosed. Accompanying effusion in the bursa of patients with tendon injuries was found in 9 cases. Conclusion. Ultrasonography allowed visualization and objective assessment of the type and the extent of traumatic pathomorphological changes of muscles and tendons. Such diagnostic possibilities of ultrasonography are especially important in the choice of appropriate therapy.

  6. Australian football players' Achilles tendons respond to game loads within 2 days: an ultrasound tissue characterisation (UTC) study.

    Science.gov (United States)

    Rosengarten, Samuel D; Cook, Jill L; Bryant, Adam L; Cordy, Justin T; Daffy, John; Docking, Sean I

    2015-02-01

    The Achilles tendon is a tissue that responds to mechanical loads at a molecular and cellular level. In vitro and in vivo studies have shown that the expression of anabolic and/or catabolic proteins can change within hours of loading and return to baseline levels within 72 h. These biochemical changes have not been correlated with changes in whole tendon structure on imaging. We examined the nature and temporal sequence of changes in Achilles tendon structure in response to competitive game loads in elite Australian football players. Elite male Australian football players with no history of Achilles tendinopathy were recruited. Achilles tendon structure was quantified using ultrasound tissue characterisation (UTC) imaging, a valid and reliable measure of intratendinous structure, the day prior to the match (day 0), and then reimaged on days 1, 2 and 4 postgame. Of the 18 participants eligible for this study, 12 had no history of tendinopathy (NORM) and 6 had a history of patellar or hamstring tendinopathy (TEN). Differences in baseline UTC echopattern were observed between the NORM and TEN groups, with the Achilles of the TEN group exhibiting altered UTC echopattern, consistent with a slightly disorganised tendon structure. In the NORM group, a significant reduction in echo-type I (normal tendon structure) was seen on day 2 (p=0.012) that returned to baseline on day 4. There was a transient change in UTC echopattern in the Achilles tendon as a result of an Australian football game in individuals without a history of lower limb tendinopathy. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Spontaneous Achilles tendon rupture in alkaptonuria

    Directory of Open Access Journals (Sweden)

    Omar A. Alajoulin

    2015-12-01

    Full Text Available Alkaptonuria (AKU is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA. Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis, early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations.

  8. Spontaneous Achilles tendon rupture in alkaptonuria.

    Science.gov (United States)

    Alajoulin, Omar A; Alsbou, Mohammed S; Ja'afreh, Somayya O; Kalbouneh, Heba M

    2015-12-01

    Alkaptonuria (AKU) is a rare inborn metabolic disease characterized by accumulation of homogentisic acid (HGA). Excretion of HGA in urine causes darkening of urine and its deposition in connective tissues causes dark pigmentation (ochronosis), early degeneration of articular cartilage, weakening of the tendons, and subsequent rupture. In this case report, we present a rare case of a patient presented with unilateral spontaneous rupture of Achilles tendon due to AKU. The patient developed most of the orthopedic manifestations of the disease earlier than typical presentations. Alkaptonuria patients should avoid strenuous exercises and foot straining especially in patients developing early orthopedic manifestations.

  9. [Development of Achilles tendon rupture in skiing].

    Science.gov (United States)

    Suckert, K; Benedetto, K P; Vogel, A

    1983-06-01

    This is an analysis of decline of rupture of the Achilles tendon in skiing while there is a steady increase of skiing injuries. Three groups, equipped with three different types of ski boots were observed once on a plane slope on the other hand on a bump track. The simultaneous size of angle of knee and ankle was measured by telemetry. The high plastic ski boot, which obstructs the ankle forward and lateral is apart from the rise of heel in the boot, the safety binding and the new skiing style the main reason for decline of rupture of the Achilles tendon in skiing.

  10. Development and evaluation of a removable tissue-engineered muscle with artificial tendons.

    Science.gov (United States)

    Nakamura, Tomohiro; Takagi, Shunya; Kamon, Takafumi; Yamasaki, Ken-Ichi; Fujisato, Toshia

    2017-02-01

    Tissue-engineered skeletal muscles were potentially useful as physiological and biochemical in vitro models. Currently, most of the similar models were constructed without tendons. In this study, we aimed to develop a simple, highly versatile tissue-engineered muscle with artificial tendons, and to evaluate the contractile, histological and molecular dynamics during differentiation. C2C12 cells were embedded in a cold type-І collagen gel and placed between two artificial tendons on a silicone sheet. The construct shrank and tightly attached to the artificial tendons with differentiation, finally detaching from the silicone sheet within 1 week of culture onset. We successfully developed a tissue-engineered skeletal muscle with two artificial tendons from C2C12 myoblasts embedded in type-І collagen gel. The isometric twitch contractile force (TCF) significantly increased during differentiation. Time to Peak Tension (TPT) and Half-Relaxation Time (1/2RT) were significantly shortened during differentiation. Myogenic regulatory factors were maximally expressed at 2 weeks, and subsequently decreased at 3 weeks of culture. Histological analysis indicated that myotube formation increased markedly from 2 weeks and well-ordered sarcomere structures were observed on the surface of the 3D engineered muscle at 3 weeks of culture. These results suggested that robust muscle structure occurred by 3 weeks in the tissue-engineered skeletal muscle. Moreover, during the developmental process, the artificial tendons might contribute to well-ordered sarcomere formation. Our results indicated that this simple culture system could be used to evaluate the effects of various pharmacological and mechanical cues on muscle contractility in a variety of research areas. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  11. [Effects of exogenous prostaglandin E2 on collagen content of Achilles tendon of rabbits in vivo].

    Science.gov (United States)

    Li, Hui; Tang, Kanglai; Deng, Yinshuan; Xie, Meiming; Chang, Dehai; Tao, Xu; Xu, Jianzhong

    2012-03-01

    Prostaglandin E2 (PGE2) production increases in human tendon fibroblasts after the tendon injuries and repetitive mechanical loading in vitro. To analyze the relations between PGE2 and tendinopathy by observing the changes of collagen content and proportion after the Achilles tendon of rabbits is repeatedly exposed to PGE2. Twenty-four Japanese rabbits (aged 3-4 months, weighing 2.0-2.5 kg, and male or female) were equally randomized into 2 groups according to injection dose of PGE2: low dose group (50 ng) and high dose group (500 ng). Corresponding PGE2 (0.2 mL) was injected into the middle segment of the Achilles tendon of hindlimb, the same dose saline into the same site of the other side as controls once a week for 4 weeks or 8 weeks. The Achilles tendons were harvested at 4 and 8 weeks after injection. HE staining was used to observe the cell structure and matrix, and picric acid-sirius red staining to observe the distribution and types of collagen fibers, and transmission electron microscopy was used to measure the density of the unit area and diameter of collagen fibers. HE staining showed that collagen structural damage was observed in low dose and high dose groups. Picric acid-sirius red staining showed that the content of type I collagen significantly decreased while the content of type III collagen significantly increased in experimental side of 2 groups at 4 and 8 weeks after injection when compared with control sides (P Achilles tendon of rabbit to PGE2 can cause the decrease of type I collagen, the increase of type III collagen, the reverse ratio of type I to type III, reduced unit density of collagen fibers, and thinner collagen fibers diameter, which is related with tendinopathy.

  12. Isolated Subscapularis Repair in Irreparable Posterosuperior Massive Rotator Cuff Tears Involving the Subscapularis Tendon.

    Science.gov (United States)

    Kim, Sung-Jae; Choi, Yun-Rak; Jung, Min; Lee, Won-Yong; Chun, Yong-Min

    2017-05-01

    No previous study has examined whether isolated subscapularis tendon repair in irreparable posterosuperior massive rotator tears involving the subscapularis tendon in relatively young patients without arthritis can yield satisfactory outcomes. We hypothesized that this procedure would produce favorable outcomes in patients who might otherwise be candidates for reverse arthroplasty. Case series; Level of evidence, 4. This retrospective study included 24 patients in their 50s and 60s, without shoulder arthritis, who underwent arthroscopic isolated subscapularis repair for an irreparable massive rotator cuff tear involving the subscapularis tendon. Preoperative and postoperative visual analog scale (VAS) pain scores, subjective shoulder values (SSVs), University of California at Los Angeles (UCLA) shoulder scores, American Shoulder and Elbow Surgeons (ASES) scores, subscapularis strength (modified bell-press test; maximum of 5), and shoulder active range of motion (ROM) were assessed. Postoperative magnetic resonance arthrography (MRA) was performed 6 months postoperatively to assess structural integrity of the repaired subscapularis. At a mean 34.8 months (range, 24-49 months) of follow-up, VAS pain scores (improved from 7.1 to 2.5), SSVs (33.3 to 75.2), ASES scores (35.9 to 76.0), UCLA shoulder scores (11.6 to 24.8), subscapularis strength, and ROM were significantly improved compared with preoperative measurements ( P rotation improved significantly ( P rotation exhibited no significant improvement. Follow-up MRA was performed in 22 patients (92%) and showed retear of the repaired subscapularis in 6 (27% of the 22). Isolated repair of the subscapularis tendon in irreparable massive rotator cuff tears involving the subscapularis tendon yielded satisfactory short-term outcomes and structural integrity in patients in their 50s and 60s without arthritis. If patients with irreparable massive rotator cuff tears involving the subscapularis tendon are relatively young or

  13. Chiasma crurale: intersection of the tibialis posterior and flexor digitorum longus tendons above the ankle. Magnetic resonance imaging-anatomic correlation in cadavers

    Energy Technology Data Exchange (ETDEWEB)

    Buck, Florian M. [VA San Diego Medical Center, Department of Radiology, San Diego, CA (United States); Institut fuer Diagnostische Radiologie, Zurich (Switzerland); Gheno, Ramon; Nico, Marcelo A.C.; Trudell, Debra J.; Resnick, Donald [VA San Diego Medical Center, Department of Radiology, San Diego, CA (United States); Haghighi, Parviz [VA San Diego Medical Center, Department of Pathology, San Diego, CA (United States)

    2010-06-15

    To determine the precise anatomy and magnetic resonance (MR) imaging appearance of the chiasma crurale in cadavers, paying special attention to degenerative changes Twelve fresh human ankles were harvested from 11 nonembalmed cadavers (mean age at death 77 years) and used according to institutional guidelines. MR imaging and MR tenography were used to investigate the anatomy of the chiasma crurale using proton density-weighted sequences. The gross anatomy of the chiasma crurale was evaluated and compared to the MR imaging findings. Histology was used to elucidate further the structure of the chiasma crurale. Above the chiasma, five specimens had a small amount of fat tissue between the tibialis posterior and flexor digitorum longus tendon. In all specimens both tendons had a sheath below the chiasma but not above it. At the central portion of the chiasma there was no soft tissue between the tendons, except in two specimens that showed an anatomic variant consisting of a thick septum connecting the tibial periosteum and the deep transverse fascia of the leg. In MR images, eight specimens showed what were believed to be degenerative changes in the tendons at the level of the chiasma. However, during gross inspection and histologic analysis of the specimens, there was no tendon degeneration visible. At the central portion of the chiasma, there is no tissue between the tibialis posterior and flexor digitorum longus tendons unless there is an anatomic variant. At the chiasma crurale, areas with irregular tendon surfaces are normal findings and are not associated with tendon degeneration (fraying). (orig.)

  14. Terminal sterilization of equine-derived decellularized tendons for clinical use

    International Nuclear Information System (INIS)

    Pellegata, Alessandro F.; Bottagisio, Marta; Boschetti, Federica; Ferroni, Marco; Bortolin, Monica; Drago, Lorenzo; Lovati, Arianna B.

    2017-01-01

    In the last few years, the demand for tissue substitutes has increased and decellularized matrices has been widely proposed in the medical field to restore severe damages thanks to high biocompatibility and biomechanical properties similar to the native tissues. However, biological grafts represent a potential source of contamination and disease transmission; thus, there is the need to achieve acceptable levels of sterility. Several sterilization methods have been investigated with no consensus on the outcomes in terms of minimizing structural damages and preserving functional features of the decellularized matrix for transplantation in humans. With the aim of making decellularized tendons safe for clinical use, we evaluated the cytocompatibility, and biochemical, structural and biomechanical variations of decellularized equine tendons sterilized with peracetic acid or β-irradiation and differently wet- or dry- stored at 4 °C or − 80 °C, respectively. Considering that both sterilization and long-term storage are crucial steps that could not be avoided, our results pointed at ionizing β-rays as terminal sterilization method for decellularized grafts followed by frozen dry storage. Indeed, this approach can maintain the integrity of collagen-based structures and can avoid biomechanical changes, thus making xenogeneic decellularized tendons a promising candidate for clinical use. - Highlights: • A decellularized tendon matrix has been generated. • The sterility of the decellularized matrix is mandatory for transplantation. • β-irradiation and cold storage preserve the matrix structure and biomechanics.

  15. Terminal sterilization of equine-derived decellularized tendons for clinical use

    Energy Technology Data Exchange (ETDEWEB)

    Pellegata, Alessandro F. [Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Bottagisio, Marta [Cell and Tissue Engineering Laboratory, IRCCS Galeazzi Orthopaedic Institute, Via Riccardo Galeazzi 4, 20161 Milan (Italy); Boschetti, Federica; Ferroni, Marco [Department of Chemistry, Materials and Chemical Engineering Giulio Natta, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milan (Italy); Bortolin, Monica [Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopaedic Institute, Via Riccardo Galeazzi 4, 20161 Milan (Italy); Drago, Lorenzo [Laboratory of Clinical Chemistry and Microbiology, IRCCS Galeazzi Orthopaedic Institute, Via Riccardo Galeazzi 4, 20161 Milan (Italy); Department of Biomedical Science for Health, University of Milan, via Luigi Mangiagalli 31, 20133 Milan (Italy); Lovati, Arianna B., E-mail: arianna.lovati@grupposandonato.it [Cell and Tissue Engineering Laboratory, IRCCS Galeazzi Orthopaedic Institute, Via Riccardo Galeazzi 4, 20161 Milan (Italy)

    2017-06-01

    In the last few years, the demand for tissue substitutes has increased and decellularized matrices has been widely proposed in the medical field to restore severe damages thanks to high biocompatibility and biomechanical properties similar to the native tissues. However, biological grafts represent a potential source of contamination and disease transmission; thus, there is the need to achieve acceptable levels of sterility. Several sterilization methods have been investigated with no consensus on the outcomes in terms of minimizing structural damages and preserving functional features of the decellularized matrix for transplantation in humans. With the aim of making decellularized tendons safe for clinical use, we evaluated the cytocompatibility, and biochemical, structural and biomechanical variations of decellularized equine tendons sterilized with peracetic acid or β-irradiation and differently wet- or dry- stored at 4 °C or − 80 °C, respectively. Considering that both sterilization and long-term storage are crucial steps that could not be avoided, our results pointed at ionizing β-rays as terminal sterilization method for decellularized grafts followed by frozen dry storage. Indeed, this approach can maintain the integrity of collagen-based structures and can avoid biomechanical changes, thus making xenogeneic decellularized tendons a promising candidate for clinical use. - Highlights: • A decellularized tendon matrix has been generated. • The sterility of the decellularized matrix is mandatory for transplantation. • β-irradiation and cold storage preserve the matrix structure and biomechanics.

  16. Effect of differences in tendon properties on functionality of the passive stay apparatus in horses

    NARCIS (Netherlands)

    Gussekloo, S.W.S.; Lankester, J.; Kersten, W.; Back, W.

    2011-01-01

    Objective—To determine the effect of differences in structural and mechanical tendon properties on functionality of the passive stay apparatus in horses. Sample—5 forelimbs each from nondwarf Friesians, dwarf Friesians, and ponies. Procedures—Harvested forelimbs were loaded to test the passive stay

  17. Differences in tendon properties in elite badminton players with or without patellar tendinopathy

    DEFF Research Database (Denmark)

    Couppé, Christian; Kongsgaard, M; Aagaard, Per

    2013-01-01

    The aim of this study was to examine the structural and mechanical properties of the patellar tendon in elite male badminton players with and without patellar tendinopathy. Seven players with unilateral patellar tendinopathy (PT group) on the lead extremity (used for forward lunge) and nine players...

  18. Monitoring of Grouting Compactness in a Post-Tensioning Tendon Duct Using Piezoceramic Transducers

    Directory of Open Access Journals (Sweden)

    Tianyong Jiang

    2016-08-01

    Full Text Available A post-tensioning tendon duct filled with grout can effectively prevent corrosion of the reinforcement, maintain bonding behavior between the reinforcement and concrete, and enhance the load bearing capacity of concrete structures. In practice, grouting of the post-tensioning tendon ducts always causes quality problems, which may reduce structural integrity and service life, and even cause accidents. However, monitoring of the grouting compactness is still a challenge due to the invisibility of the grout in the duct during the grouting process. This paper presents a stress wave-based active sensing approach using piezoceramic transducers to monitor the grouting compactness in real time. A segment of a commercial tendon duct was used as research object in this study. One lead zirconate titanate (PZT piezoceramic transducer with marble protection, called a smart aggregate (SA, was bonded on the tendon and installed in the tendon duct. Two PZT patch sensors were mounted on the top outside surface of the duct, and one PZT patch sensor was bonded on the bottom outside surface of the tendon duct. In the active sensing approach, the SA was used as an actuator to generate a stress wave and the PZT sensors were utilized to detect the wave response. Cement or grout in the duct functions as a wave conduit, which can propagate the stress wave. If the cement or grout is not fully filled in the tendon duct, the top PZT sensors cannot receive much stress wave energy. The experimental procedures simulated four stages during the grout pouring process, which includes empty status, half grouting, 90% grouting, and full grouting of the duct. Experimental results show that the bottom PZT sensor can detect the signal when the grout level increases towards 50%, when a conduit between the SA and PZT sensor is formed. The top PZT sensors cannot receive any signal until the grout process is completely finished. The wavelet packet-based energy analysis was adopted in this

  19. The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model.

    Science.gov (United States)

    Li, Shengkun; Ma, Kui; Li, Hong; Jiang, Jia; Chen, Shiyi

    2016-01-01

    The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET) artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA) is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired with PET were assigned to PET group; the other eight rabbits repaired with PET along with injection of HE were assigned to HA-PET group. All rabbits were sacrificed at 4 and 8 weeks postoperatively for biomechanical and histological examination. The HA-PET group revealed higher biomechanical property compared with the PET group. Histologically, more collagen tissues grew into the HA-PET group compared with PET group. In conclusion, application of sodium hyaluronate can improve the healing of Achilles tendon reconstruction with polyethylene terephthalate artificial ligament.

  20. Peroneal tendon displacement accompanying intra-articular calcaneal fractures.

    Science.gov (United States)

    Toussaint, Rull James; Lin, Darius; Ehrlichman, Lauren K; Ellington, J Kent; Strasser, Nicholas; Kwon, John Y

    2014-02-19

    Peroneal tendon displacement (subluxation or dislocation) accompanying an intra-articular calcaneal fracture is often undetected and under-treated. The goals of this study were to determine (1) the prevalence of peroneal tendon displacement accompanying intra-articular calcaneal fractures, (2) the association of tendon displacement with fracture classifications, (3) the association of tendon displacement with heel width, and (4) the rate of missed diagnosis of the tendon displacement on radiographs and computed tomography (CT) scans and the resulting treatment rate. A retrospective radiographic review of all calcaneal fractures presenting at three institutions from June 30, 2006, to June 30, 2011, was performed. CT imaging of 421 intra-articular calcaneal fractures involving the posterior facet was available for review. The prevalence of peroneal tendon displacement was noted and its associations with fracture classification and heel width were evaluated. Peroneal tendon displacement was identified in 118 (28.0%) of the 421 calcaneal fracture cases. The presence of tendon displacement was significantly associated with joint-depression fractures compared with tongue-type fractures (p displacement had been identified in the radiology reports. Although sixty-five (55.1%) of the fractures with tendon displacement had been treated with internal fixation, the tendon displacement was treated surgically in only seven (10.8%) of these cases. Analysis of CT images showed a 28% prevalence of peroneal tendon displacement accompanying intra-articular calcaneal fractures. Surgeons and radiologists are encouraged to consider this association.

  1. Advanced age diminishes tendon-to-bone healing in a rat model of rotator cuff repair.

    Science.gov (United States)

    Plate, Johannes F; Brown, Philip J; Walters, Jordan; Clark, John A; Smith, Thomas L; Freehill, Michael T; Tuohy, Christopher J; Stitzel, Joel D; Mannava, Sandeep

    2014-04-01

    Advanced patient age is associated with recurrent tearing and failure of rotator cuff repairs clinically; however, basic science studies have not evaluated the influence of aging on tendon-to-bone healing after rotator cuff repair in an animal model. Hypothesis/ This study examined the effect of aging on tendon-to-bone healing in an established rat model of rotator cuff repair using the aged animal colony from the National Institute on Aging of the National Institutes of Health. The authors hypothesized that normal aging decreases biomechanical strength and histologic organization at the tendon-to-bone junction after acute repair. Controlled laboratory study. In 56 F344xBN rats, 28 old and 28 young (24 and 8 months of age, respectively), the supraspinatus tendon was transected and repaired. At 2 or 8 weeks after surgery, shoulder specimens underwent biomechanical testing to compare load-to-failure and load-relaxation response between age groups. Histologic sections of the tendon-to-bone interface were assessed with hematoxylin and eosin staining, and collagen fiber organization was assessed by semiquantitative analysis of picrosirius red birefringence under polarized light. Peak failure load was similar between young and old animals at 2 weeks after repair (31% vs 26% of age-matched uninjured controls, respectively; P > .05) but significantly higher in young animals compared with old animals 8 weeks after repair (86% vs 65% of age-matched uninjured controls, respectively; P repair, fibroblasts appeared more organized and uniformly aligned in young animals on hematoxylin and eosin slides compared with old animals. Collagen birefringence analysis of the tendon-to-bone junction demonstrated that young animals had increased collagen fiber organization and similar histologic structure compared with age-matched controls (53.7 ± 2.4 gray scales; P > .05). In contrast, old animals had decreased collagen fiber organization and altered structure compared with age

  2. Variation in the insertion of the palmaris longus tendon

    Science.gov (United States)

    Sunil, Vinutha; Rajanna, Shubha; Gitanjali; Kadaba, Jayanthi

    2015-01-01

    The palmaris longus is harvested as a tendon graft in various surgical procedures. We herein report the variations in the insertion of the palmaris longus tendon. During a routine dissection, a rare variation in the insertion of the palmaris longus tendon was observed. In the left forearm, the palmaris longus tendon bifurcated, while in the right forearm, the palmaris longus tendon trifurcated, giving rise to an accessory muscle, which passed superficial to the ulnar artery and ulnar nerve. The accessory muscle was supplied by a deep branch of the ulnar nerve, and the ulnar artery was observed to be tortuous. During reconstructive surgeries, surgeons should bear in mind the accessory muscle. Also, since the palmaris longus muscle provides a very useful graft in tendon surgery, every surgeon should be aware of the variations in the insertion of the palmaris longus tendon. PMID:25640108

  3. A Rare Case of Simultaneous Acute Bilateral Quadriceps Tendon Rupture and Unilateral Achilles Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Wei Yee Leong

    2013-07-01

    Full Text Available Introduction: There have been multiple reported cases of bilateral quadriceps tendon ruptures (QTR in the literature. These injuries frequently associated with delayed diagnosis, which results in delayed surgical treatment. In very unusual cases, bilateral QTRs can be associated with other simultaneous tendon ruptures. Case Report: We present a rare case of bilateral QTR with a simultaneous Achilles Tendon Rupture involving a 31 years old Caucasian man who is a semi-professional body builder taking anabolic steroids. To date bilateral QTR with additional TA rupture has only been reported once in the literature and to our knowledge this is the first reported case of bilateral QTR and simultaneous TA rupture in a young, fit and healthy individual. Conclusion: The diagnosis of bilateral QTR alone can sometimes be challenging and the possibility of even further tendon injuries should be carefully assessed. A delay in diagnosis could result in delay in treatment and potentially worse outcome for the patient. Keywords: Quadriceps tendon rupture; Achilles tendon rupture; Bilateral.

  4. Tendoscopy of the posterior tibial tendon

    NARCIS (Netherlands)

    van Dijk, C. N.; Kort, N.; Scholten, P. E.

    1997-01-01

    An anatomic cadaver study was performed and subsequently, in a prospective study, diagnostic and therapeutic tendoscopy (tendon sheath endoscopy) was performed in 16 consecutive patients with a history of persistent posteromedial ankle pain for at least 6 months. All patients had pain on palpation

  5. A posterior tibial tendon skipping rope

    NARCIS (Netherlands)

    van Sterkenburg, M. N.; Haverkamp, D.; van Dijk, C. N.; Kerkhoffs, G. M. M. J.

    2010-01-01

    This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord

  6. Radiographic Features of Acute Patellar Tendon Rupture.

    Science.gov (United States)

    Fazal, Muhammad Ali; Moonot, Pradeep; Haddad, Fares

    2015-11-01

    The purpose of our study was to assess soft tissue features of acute patellar tendon rupture on lateral knee radiograph that would facilitate early diagnosis. The participants were divided into two groups of 35 patients each. There were 28 men and seven women with a mean age of 46 years in the control group and 26 men and nine women with a mean age of 47 years in the rupture group. The lateral knee radiograph of each patient was evaluated for Insall-Salvati ratio for patella alta, increased density of the infrapatellar fat pad, appearance of the soft tissue margin of the patellar tendon and bony avulsions. In the rupture group there were three consistent soft tissue radiographic features in addition to patellar alta. These were increased density of infrapatellar fat pad; loss of sharp, well-defined linear margins of the patellar tendon and angulated wavy margin of the patellar tendon while in the control group these features were not observed. The soft tissue radiographic features described in the rupture group are consistent and reliable. When coupled with careful clinical assessment, these will aid in early diagnosis and further imaging will be seldom required. © 2015 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

  7. Engaging Stem Cells for Customized Tendon Regeneration

    Directory of Open Access Journals (Sweden)

    Hatim Thaker

    2012-01-01

    Full Text Available The need for a consistent therapeutic approach to tendon injury repair is long overdue. Patients with tendon microtears or full ruptures are eligible for a wide range of invasive and non invasive interventions, often subjectively decided by the physician. Surgery produces the best outcomes, and while studies have been conducted to optimize graft constructs and to track outcomes, the data from these studies have been inconclusive on the whole. What has been established is a clear understanding of healthy tendon architecture and the inherent process of healing. With this knowledge, tissue regeneration efforts have achieved immense progress in scaffold design, cell line selection, and, more recently, the appropriate use of cytokines and growth factors. This paper evaluates the plasticity of bone-marrow-derived stem cells and the elasticity of recently developed biomaterials towards tendon regeneration efforts. Mesenchymal stem cells (MSCs, hematopoietic progenitor cells, and poly(1,8-octanediol co-citrate scaffolds (POC are discussed in the context of established grafting strategies. With POC scaffolds to cradle the growth of MSCs and hematopoietic progenitor cells, developing a fibroelastic network guided by cytokines and growth factors may contribute towards consistent graft constructs, enhanced functionality, and better patient outcomes.

  8. [The history of flexor tendon surgery].

    Science.gov (United States)

    Chamay, A

    1997-01-01

    Flexor tendon injuries were already treated in antiquity by Hippocrates, Galien and Avicenne. Since the Renaissance, other surgeons have attempted to repair flexor tendon injuries, but without success due to problems related to unsuitable materials and ignorance of the basic rules of asepsis and the absence of antiseptics until the second half of the 19th century. The first successful flexor tendon grafts in man were performed by K. Biesalski in 1910, E. Lexer in 1912 and L. Mayer in 1916. These three authors published their series of grafts and described in detail the anatomical, physiological and technical principles to be respected. St. Bunnell, in 1918, developed various pull-out direct suture procedures, but faced with the problems of adhesions, he abandoned this technique and proposed not to repair flexors in the digital tunnels but to graft them. He defined the famous zone which he called No man's land, which subsequently became Claude Verdan's zone II, in 1959. In 1960, C. Verdan published his first series of sutures maintained by 2 pins in zone II with comparable results to those obtained after grafting. In 1967, H. Kleinert, with his mobile suture, became the leader of direct tendon repair in zone II. 2-stage grafts were introduced in 1965 under the impetus of J. Hunter, who revised and popularized the studies conducted by A. Bassett and R.E. Caroll in 1950.

  9. Collagen V expression is crucial in regional development of the supraspinatus tendon.

    Science.gov (United States)

    Connizzo, Brianne K; Adams, Sheila M; Adams, Thomas H; Birk, David E; Soslowsky, Louis J

    2016-12-01

    Manipulations in cell culture and mouse models have demonstrated that reduction of collagen V results in altered fibril structure and matrix assembly. A tissue-dependent role for collagen V in determining mechanical function was recently established, but its role in determining regional properties has not been addressed. The objective of this study was to define the role(s) of collagen V expression in establishing the site-specific properties of the supraspinatus tendon. The insertion and midsubstance of tendons from wild type, heterozygous and tendon/ligament-specific null mice were assessed for crimp morphology, fibril morphology, cell morphology, as well as total collagen and pyridinoline cross-link (PYD) content. Fibril morphology was altered at the midsubstance of both groups with larger, but fewer, fibrils and no change in cell morphology or collagen compared to the wild type controls. In contrast, a significant disruption of fibril assembly was observed at the insertion site of the null group with the presence of structurally aberrant fibrils. Alterations were also present in cell density and PYD content. Altogether, these results demonstrate that collagen V plays a crucial role in determining region-specific differences in mouse supraspinatus tendon structure. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2154-2161, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  10. Low-Magnitude, High-Frequency Vibration Fails to Accelerate Ligament Healing but Stimulates Collagen Synthesis in the Achilles Tendon.

    Science.gov (United States)

    Thompson, William R; Keller, Benjamin V; Davis, Matthew L; Dahners, Laurence E; Weinhold, Paul S

    2015-05-01

    Low-magnitude, high-frequency vibration accelerates fracture and wound healing and prevents disuse atrophy in musculoskeletal tissues. To investigate the role of low-magnitude, high-frequency vibration as a treatment to accelerate healing of an acute ligament injury and to examine gene expression in the intact Achilles tendon of the injured limb after low-magnitude, high-frequency vibration. Controlled laboratory study. Complete surgical transection of the medial collateral ligament (MCL) was performed in 32 Sprague-Dawley rats, divided into control and low-magnitude, high-frequency vibration groups. Low-magnitude, high-frequency vibration started on postoperative day 2, and rats received vibration for 30 minutes a day for 12 days. All rats were sacrificed 2 weeks after the operation, and their intact and injured MCLs were biomechanically tested or used for histological analysis. Intact Achilles tendons from the injured limb were evaluated for differences in gene expression. Mechanical testing revealed no differences in the ultimate tensile load or the structural stiffness between the control and vibration groups for either the injured or intact MCL. Vibration exposure increased gene expression of collagen 1 alpha (3-fold), interleukin 6 (7-fold), cyclooxygenase 2 (5-fold), and bone morphogenetic protein 12 (4-fold) in the intact Achilles tendon when compared with control tendons ( P frequency vibration treatment, significant enhancements in gene expression were observed in the intact Achilles tendon. These included collagen, several inflammatory cytokines, and growth factors critical for tendons. As low-magnitude, high-frequency vibration had no negative effects on ligament healing, vibration therapy may be a useful tool to accelerate healing of other tissues (bone) in multitrauma injuries without inhibiting ligament healing. Additionally, the enhanced gene expression in response to low-magnitude, high-frequency vibration in the intact Achilles tendon suggests the

  11. The development and morphogenesis of the tendon-to-bone insertion What development can teach us about healing

    Science.gov (United States)

    Thomopoulos, Stavros; Genin, Guy M.; Galatz, Leesa M.

    2013-01-01

    The attachment of dissimilar materials is a major challenge because of the high levels of stress that develop at such interfaces. An effective solution to this problem develops at the attachment of tendon (a compliant “soft tissue”) to bone (a stiff “hard tissue”). This tissue, the “enthesis”, transitions from tendon to bone through gradations in structure, composition, and mechanical properties. These gradations are not regenerated during tendon-to-bone healing, leading to a high incidence of failure after surgical repair. Understanding the development of the enthesis may allow scientists to develop treatments that regenerate the natural tendon-to-bone insertion. Recent work has demonstrated that both biologic and mechanical factors drive the development and morphogenesis of the enthesis. A cascade of biologic signals similar to those seen in the growth plate promotes mineralization of cartilage on the bony end of the enthesis and the formation of fibrocartilage on the tendon end of the enthesis. Mechanical loading is also necessary for the development of the enthesis. Removal of muscle load impairs the formation of bone, fibrocartilage, and tendon at the developing enthesis. This paper reviews recent work on the development of the enthesis, with an emphasis on the roles of biologic and mechanical factors. PMID:20190378

  12. Changes in histoanatomical distribution of types I, III and V collagen promote adaptative remodeling in posterior tibial tendon rupture

    Directory of Open Access Journals (Sweden)

    Érika Satomi

    2008-01-01

    Full Text Available INTRODUCTION: Posterior tibial tendon dysfunction is a common cause of adult flat foot deformity, and its etiology is unknown. PURPOSE: In this study, we characterized the morphologic pattern and distribution of types I, III and V collagen in posterior tibial tendon dysfunction. METHOD: Tendon samples from patients with and without posterior tibial tendon dysfunction were stained by immunofluorescence using antibodies against types I, III and V collagen. RESULTS: Control samples showed that type V deposited near the vessels only, while surgically obtained specimens displayed type V collagen surrounding other types of collagen fibers in thicker adventitial layers. Type III collagen levels were also increased in pathological specimens. On the other hand, amounts of collagen type I, which represents 95% of the total collagen amount in normal tendon, were decreased in pathological specimens. CONCLUSION: Fibrillogenesis in posterior tibial tendon dysfunction is altered due to higher expression of types III and V collagen and a decreased amount of collagen type I, which renders the originating fibrils structurally less resistant to mechanical forces.

  13. Engineered stem cell niche matrices for rotator cuff tendon regenerative engineering.

    Directory of Open Access Journals (Sweden)

    M Sean Peach

    Full Text Available Rotator cuff (RC tears represent a large proportion of musculoskeletal injuries attended to at the clinic and thereby make RC repair surgeries one of the most widely performed musculoskeletal procedures. Despite the high incidence rate of RC tears, operative treatments have provided minimal functional gains and suffer from high re-tear rates. The hypocellular nature of tendon tissue poses a limited capacity for regeneration. In recent years, great strides have been made in the area of tendonogenesis and differentiation towards tendon cells due to a greater understanding of the tendon stem cell niche, development of advanced materials, improved scaffold fabrication techniques, and delineation of the phenotype development process. Though in vitro models for tendonogenesis have shown promising results, in vivo models have been less successful. The present work investigates structured matrices mimicking the tendon microenvironment as cell delivery vehicles in a rat RC tear model. RC injuries augmented with a matrix delivering rat mesenchymal stem cells (rMSCs showed enhanced regeneration over suture repair alone or repair with augmentation, at 6 and 12-weeks post-surgery. The local delivery of rMSCs led to increased mechanical properties and improved tissue morphology. We hypothesize that the mesenchymal stem cells function to modulate the local immune and bioactivity environment through autocrine/paracrine and/or cell homing mechanisms. This study provides evidence for improved tendon healing with biomimetic matrices and delivered MSCs with the potential for translation to larger, clinical animal models. The enhanced regenerative healing response with stem cell delivering biomimetic matrices may represent a new treatment paradigm for massive RC tendon tears.

  14. Changes in Achilles tendon mechanical properties following eccentric heel drop exercise are specific to the free tendon.

    Science.gov (United States)

    Obst, S J; Newsham-West, R; Barrett, R S

    2016-04-01

    Mechanical loading of the Achilles tendon during isolated eccentric contractions could induce immediate and region-dependent changes in mechanical properties. Three-dimensional ultrasound was used to examine the immediate effect of isolated eccentric exercise on the mechanical properties of the distal (free tendon) and proximal (gastrocnemii) regions of the Achilles tendon. Participants (n = 14) underwent two testing sessions in which tendon measurements were made at rest and during a 30% and 70% isometric plantar flexion contractions immediately before and after either: (a) 3 × 15 eccentric heel drops or (b) 10-min rest. There was a significant time-by-session interaction for free tendon length and strain for all loading conditions (P tendon length and strain at all contraction intensities after eccentric exercise (P tendon for any of the measured parameters. Immediate changes in Achilles tendon mechanical properties were specific to the free tendon and consistent with changes due to mechanical creep. These findings suggest that the mechanical properties of the free tendon may be more vulnerable to change with exercise compared with the gastrocnemii aponeurosis or tendon. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. [Reconstruction of the extensor pollicis longus tendon by transposition of the extensor indicis tendon].

    Science.gov (United States)

    Loos, A; Kalb, K; Van Schoonhoven, J; Landsleitner Dagger, B

    2003-12-01

    Rupture of the extensor pollicis longus-tendon (EPL) is a frequent complication after distal radius fractures. Other traumatic and non-traumatic reasons for this tendon lesion are known, including a theory about a disorder in the blood supply to the tendon itself. We examined 40 patients after reconstruction of the EPL-tendon in a mean follow-up time of 30 months. All patients were clinically examined and a DASH questionnaire was answered by all patients. The method to reconstruct the EPL-tendon was the transposition of the extensor indicis-tendon. After the operations the thumb was put in a splint for four weeks in a "hitch-hiker's-position". 31 ruptures of the tendon (77.5 %) were a result of trauma. In 20 of them (50 %) a distal radius fracture had occurred. Clinical examination included measurements of the movement of the thumb- and index-finger joints, the grip strength and the maximal span of the hand. Significant differences were not found. The isolated extension of the index finger was possible in all patients. But it was reduced in ten cases which represent 25 %. Our results were evaluated by the Geldmacher score to evaluate the reconstruction of the EPL-tendon. 20 % excellent, 65 % good, 12.5 % fair and 2.5 % poor results were reached. The Geldmacher score was used critically. We suggest its modification for the evaluation of thumb abduction. The DASH score reached a functional value of ten points which represents a very good result. In conclusion the extensor indicis-transposition is a safe method to reconstruct the EPL-tendon. Its substantial advantage is taking a healthy muscle as the motor, thereby avoiding the risk of using a degenerated muscle in late tendon reconstruction. A powerful extension of the index finger will be maintained by physical education. Generally, the loss of the extension of the index finger is negligible. It does not disturb the patients. But it has to be discussed with the patient before the operation.

  16. Collagenolytic activity is produced by rabbit ligaments and tendon

    International Nuclear Information System (INIS)

    Harper, J.; Amiel, D.; Harper, E.

    1986-01-01

    The authors examined the patellar tendon (PT), anterior cruciate ligament (ACL) and medial collateral ligament (MCL) from normal rabbits for collagenase activity. All three connective tissues contain large amounts of collagen and the catabolism of this structural protein is important to their integrity. The authors cultured each tissue in serum free medium for 14 days. Collagenase was produced by all three connective tissues after a lag period of up to 7 days, as detected by the 14 C-glycine peptide-release assay. Culture media that did not express enzyme the authors found to contain inhibitory activity. The collagenases and inhibitors from each tissue have been quantitated and characterized. After 9 days the collagenase activity for the rabbit periarticular tissues was 6.1 (PT), 4.4 (MCL) and 8.6 (ACL) units per milligram of secreted protein. The cleavage site of all three collagenases was found to be similar to that observed for rabbit skin collagenase, and generation of reaction products TC/sup A/ and TC/sup B/ was demonstrated by collagenases from PT, MCL and ACL. These results suggest that the metabolism of ligaments and tendon is regulated by the production of zymogen, active collagenase and inhibitor, similar to other connective tissues. The role of these components in joint injury and joint diseases is currently being investigated

  17. Increased mast cell numbers in a calcaneal tendon overuse model

    DEFF Research Database (Denmark)

    Pingel, Jessica; Wienecke, Jacob; Kongsgaard Madsen, Mads

    2013-01-01

    Tendinopathy is often discovered late because the initial development of tendon pathology is asymptomatic. The aim of this study was to examine the potential role of mast cell involvement in early tendinopathy using a high-intensity uphill running (HIUR) exercise model. Twenty-four male Wistar rats...... = 0.03; 2.75 ± 0.54 vs 1.17 ± 0.53, was increased in the runners. The Bonar score (P = 0.05), and the number of mast cells (P = 0.02) were significantly higher in the runners compared to the controls. Furthermore, SHGM showed focal collagen disorganization in the runners, and reduced collagen density...... (P = 0.03). IL-3 mRNA levels were correlated with mast cell number in sedentary animals. The qPCR analysis showed no significant differences between the groups in the other analyzed targets. The current study demonstrates that 7-week HIUR causes structural changes in the calcaneal tendon, and further...

  18. An age-related study of morphology and cross-link composition of collagen fibrils in the digital flexor tendons of young thoroughbred horses.

    Science.gov (United States)

    Patterson-Kane, J C; Parry, D A; Birch, H L; Goodship, A E; Firth, E C

    1997-01-01

    The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance. Consequently, the association of age and collagen fibril crosslink composition, diameter distribution and crimp morphology in the superficial and deep digital flexor tendons of Thoroughbreds up to and including three years of age has been studied. Replacement of immature crosslinks, peaking of the collagen fibril mass-average diameter and collagen fibril index, and stabilization of collagen crimp morphology changes supported the hypothesis that both digital flexor tendons become mature in structure by two years of age.

  19. Probabilistic model of ligaments and tendons: Quasistatic linear stretching

    Science.gov (United States)

    Bontempi, M.

    2009-03-01

    Ligaments and tendons have a significant role in the musculoskeletal system and are frequently subjected to injury. This study presents a model of collagen fibers, based on the study of a statistical distribution of fibers when they are subjected to quasistatic linear stretching. With respect to other methodologies, this model is able to describe the behavior of the bundle using less ad hoc hypotheses and is able to describe all the quasistatic stretch-load responses of the bundle, including the yield and failure regions described in the literature. It has two other important results: the first is that it is able to correlate the mechanical behavior of the bundle with its internal structure, and it suggests a methodology to deduce the fibers population distribution directly from the tensile-test data. The second is that it can follow fibers’ structure evolution during the stretching and it is possible to study the internal adaptation of fibers in physiological and pathological conditions.

  20. A Tendon Cell Specific RNAi Screen Reveals Novel Candidates Essential for Muscle Tendon Interaction.

    Directory of Open Access Journals (Sweden)

    Prabhat Tiwari

    Full Text Available Tendons are fibrous connective tissue which connect muscles to the skeletal elements thus acting as passive transmitters of force during locomotion and provide appropriate body posture. Tendon-derived cues, albeit poorly understood, are necessary for proper muscle guidance and attachment during development. In the present study, we used dorsal longitudinal muscles of Drosophila and their tendon attachment sites to unravel the molecular nature of interactions between muscles and tendons. We performed a genetic screen using RNAi-mediated knockdown in tendon cells to find out molecular players involved in the formation and maintenance of myotendinous junction and found 21 candidates out of 2507 RNAi lines screened. Of these, 19 were novel molecules in context of myotendinous system. Integrin-βPS and Talin, picked as candidates in this screen, are known to play important role in the cell-cell interaction and myotendinous junction formation validating our screen. We have found candidates with enzymatic function, transcription activity, cell adhesion, protein folding and intracellular transport function. Tango1, an ER exit protein involved in collagen secretion was identified as a candidate molecule involved in the formation of myotendinous junction. Tango1 knockdown was found to affect development of muscle attachment sites and formation of myotendinous junction. Tango1 was also found to be involved in secretion of Viking (Collagen type IV and BM-40 from hemocytes and fat cells.

  1. Motor responses to experimental Achilles tendon pain

    DEFF Research Database (Denmark)

    Henriksen, Marius; Aaboe, Jens; Graven-Nielsen, Thomas

    2011-01-01

    of the exercise are affected by Achilles tendon pain. Objective The authors aimed to determine the effects of experimental Achilles tendon pain on motor function during one-legged weight bearing ankle plantar and dorsal flexion exercises. Methods In a crossover study, with 16 healthy subjects tested on two......Background Achilles tendinopathies are characterised by pain and reduced function, and heavy-load exercises have been shown to be effective in the treatment of painful chronic Achilles tendinopathies. However, basic information is needed on how the biomechanics and neuromuscular control...... different days separated by 1 week, three-dimensional ground reaction forces, ankle joint kinematics and surface electromyography (EMG) of the lower leg muscles were recorded during one-legged full weight-bearing ankle plantar (concentric) and dorsal (eccentric) flexion exercises. Measurements were done...

  2. Imaging the infrapatellar tendon in the elite athlete

    International Nuclear Information System (INIS)

    Peace, K.A.L.; Lee, J.C.; Healy, J.

    2006-01-01

    Extensor mechanism injuries constitute a major cause of anterior knee pain in the elite athlete. Sonography and magnetic resonance imaging (MRI) are the imaging methods of choice when assessing the infrapatellar tendon. A comprehensive imaging review of infrapatellar tendon normal anatomy, tendinopathy, and partial/full-thickness tendon tears is provided. The value of imaging the infrapatellar tendon in clinical practice, including whether sonography can predict symptoms in asymptomatic athletes, is discussed. Acute avulsion fractures, including periosteal sleeve avulsion, and chronic avulsion injuries, including Sinding-Larsen-Johansson and Osgood-Schlatter syndromes, are shown. Mimics of infrapatellar tendon pathology, including infrapatellar plica injury, patellar tendon-lateral femoral condyle friction syndrome, and Hoffa's syndrome, are illustrated

  3. About tendon tissue regeneration in experimental radiation disease

    Energy Technology Data Exchange (ETDEWEB)

    Popov, D; Trichkova, P

    1976-01-01

    Under the conditions of experimental acute radiation disease the authors study the tendon tissue regeneration after suture of the lateral part of the gastrocnemius muscle tendon. Tendon auto and alloplasty were applied. In four postoperative periods the histological features are described in details as well as the characteristic phenomena observed during the regeneration influenced to a considerable degree by the irradiation. Round cell infiltration, large necrotic zones, erythrocyte infiltrations as well as predominance of non-specific tendon regeneration long after the surgery characterize the recovery period of the traumatically damaged tendon, nevertheless that at the end there is real tendon regeneration even though in a longer period in comparison with the controls (non-irradiated animals).

  4. Calcaneal Tendon Collagen Fiber Morphometry and Aging

    Czech Academy of Sciences Publication Activity Database

    Hadraba, Daniel; Janáček, Jiří; Filová, Eva; Lopot, F.; Paesen, R.; Fanta, O.; Jarman, A.; Nečas, A.; Ameloot, M.; Jelen, K.

    2017-01-01

    Roč. 23, č. 5 (2017), s. 1040-1047 ISSN 1431-9276 R&D Projects: GA ČR(CZ) GA16-14758S; GA MŠk(CZ) LO1309; GA MŠk(CZ) LM2015062 Institutional support: RVO:67985823 ; RVO:68378041 Keywords : collagen * aging * crimp * fiber orientation * tendon Subject RIV: EB - Genetics ; Molecular Biology; BO - Biophysics (UEM-P) OBOR OECD: Developmental biology; Biophysics (UEM-P) Impact factor: 1.891, year: 2016

  5. Engineering tendon and ligament tissues: present developments towards successful clinical products.

    Science.gov (United States)

    Rodrigues, Márcia T; Reis, Rui L; Gomes, Manuela E

    2013-09-01

    Musculoskeletal diseases are one of the leading causes of disability worldwide. Among them, tendon and ligament injuries represent an important aspect to consider in both athletes and active working people. Tendon and ligament damage is an important cause of joint instability, and progresses into early onset of osteoarthritis, pain, disability and eventually the need for joint replacement surgery. The social and economical burden associated with these medical conditions presents a compelling argument for greater understanding and expanding research on this issue. The particular physiology of tendons and ligaments (avascular, hypocellular and overall structural mechanical features) makes it difficult for currently available treatments to reach a complete and long-term functional repair of the damaged tissue, especially when complete tear occurs. Despite the effort, the treatment modalities for tendon and ligament are suboptimal, which have led to the development of alternative therapies, such as the delivery of growth factors, development of engineered scaffolds or the application of stem cells, which have been approached in this review. Copyright © 2012 John Wiley & Sons, Ltd.

  6. Fourier-transform infrared anisotropy in cross and parallel sections of tendon and articular cartilage

    Directory of Open Access Journals (Sweden)

    Bidthanapally Aruna

    2008-10-01

    Full Text Available Abstract Background Fourier Transform Infrared Imaging (FTIRI is used to investigate the amide anisotropies at different surfaces of a three-dimensional cartilage or tendon block. With the change in the polarization state of the incident infrared light, the resulting anisotropic behavior of the tissue structure is described here. Methods Thin sections (6 μm thick were obtained from three different surfaces of the canine tissue blocks and imaged at 6.25 μm pixel resolution. For each section, infrared imaging experiments were repeated thirteen times with the identical parameters except a 15° increment of the analyzer's angle in the 0° – 180° angular space. The anisotropies of amide I and amide II components were studied in order to probe the orientation of the collagen fibrils at different tissue surfaces. Results For tendon, the anisotropy of amide I and amide II components in parallel sections is comparable to that of regular sections; and tendon's cross sections show distinct, but weak anisotropic behavior for both the amide components. For articular cartilage, parallel sections in the superficial zone have the expected infrared anisotropy that is consistent with that of regular sections. The parallel sections in the radial zone, however, have a nearly isotropic amide II absorption and a distinct amide I anisotropy. Conclusion From the inconsistency in amide anisotropy between superficial to radial zone in parallel section results, a schematic model is used to explain the origins of these amide anisotropies in cartilage and tendon.

  7. Effects of no stiffness inside unbonded tendon ducts on the behavior of prestressd concrete containment vessels

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sang Hoon; Kwak, Hyo Gyong [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Jung, Rae Young; Noh, Sang Hoon [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2016-06-15

    The numerical simulation methodologies to evaluate the structural behaviors of prestressed concrete containment vessels (PCCVs) have been substantially developed in recent decades. However, there remain several issues to be investigated more closely to narrow the gap between test results and numerical simulations. As one of those issues, the effects of no stiffness inside unbonded tendon ducts on the behavior of PCCVs are investigated in this study. Duct holes for prestressing cables' passing are provided inside the containment wall and dome in one to three directions for general PCCVs. The specific stress distribution along the periphery of the prestressing duct hole and the loss of stiffness inside the hole, especially in an unbonded tendon system, are usually neglected in the analysis of PCCVs with the assumption that the duct hole is filled with concrete. However, duct holes are not small enough to be neglected. In this study, the effects of no stiffness inside the unbonded tendon system on the behaviors of PCCVs are evaluated using both analytical and numerical approaches. From the results, the effects of no stiffness in unbonded tendons need to be considered in numerical simulations for PCCVs, especially under internal pressure loading.

  8. Effects of no stiffness inside unbonded tendon ducts on the behavior of prestressd concrete containment vessels

    International Nuclear Information System (INIS)

    Noh, Sang Hoon; Kwak, Hyo Gyong; Jung, Rae Young; Noh, Sang Hoon

    2016-01-01

    The numerical simulation methodologies to evaluate the structural behaviors of prestressed concrete containment vessels (PCCVs) have been substantially developed in recent decades. However, there remain several issues to be investigated more closely to narrow the gap between test results and numerical simulations. As one of those issues, the effects of no stiffness inside unbonded tendon ducts on the behavior of PCCVs are investigated in this study. Duct holes for prestressing cables' passing are provided inside the containment wall and dome in one to three directions for general PCCVs. The specific stress distribution along the periphery of the prestressing duct hole and the loss of stiffness inside the hole, especially in an unbonded tendon system, are usually neglected in the analysis of PCCVs with the assumption that the duct hole is filled with concrete. However, duct holes are not small enough to be neglected. In this study, the effects of no stiffness inside the unbonded tendon system on the behaviors of PCCVs are evaluated using both analytical and numerical approaches. From the results, the effects of no stiffness in unbonded tendons need to be considered in numerical simulations for PCCVs, especially under internal pressure loading

  9. High stress monitoring of prestressing tendons in nuclear concrete vessels using fibre-optic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Perry, M., E-mail: marcus.perry@strath.ac.uk [Institute for Energy and Environment, University of Strathclyde, 204 George Street, Glasgow G1 1XW (United Kingdom); Yan, Z.; Sun, Z.; Zhang, L. [Aston Institute of Photonic Technologies, Aston University, Birmingham B4 7ET (United Kingdom); Niewczas, P. [Institute for Energy and Environment, University of Strathclyde, 204 George Street, Glasgow G1 1XW (United Kingdom); Johnston, M. [Civil Design Group, EDF Energy, Nuclear Generation, East Kilbride G74 5PG (United Kingdom)

    2014-03-15

    Highlights: • We weld radiation-resistant optical fibre strain sensors to steel prestressing tendons. • We prove the sensors can survive 1300 MPa stress (80% of steel's tensile strength). • Mechanical relaxation of sensors is characterised under 1300 MPa stress over 10 h. • Strain transfer between tendon and sensor remains at 69% after relaxation. • Sensors can withstand and measure deflection of tendon around a 4.5 m bend radius. - Abstract: Maintaining the structural health of prestressed concrete nuclear containments is a key element in ensuring nuclear reactors are capable of meeting their safety requirements. This paper discusses the attachment, fabrication and characterisation of optical fibre strain sensors suitable for the prestress monitoring of irradiated steel prestressing tendons. The all-metal fabrication and welding process allowed the instrumented strand to simultaneously monitor and apply stresses up to 1300 MPa (80% of steel's ultimate tensile strength). There were no adverse effects to the strand's mechanical properties or integrity. After sensor relaxation through cyclic stress treatment, strain transfer between the optical fibre sensors and the strand remained at 69%. The fibre strain sensors could also withstand the non-axial forces induced as the strand was deflected around a 4.5 m bend radius. Further development of this technology has the potential to augment current prestress monitoring practices, allowing distributed measurements of short- and long-term prestress losses in nuclear prestressed-concrete vessels.

  10. Flexible bipolar nanofibrous membranes for improving gradient microstructure in tendon-to-bone healing.

    Science.gov (United States)

    Li, Xiaoxi; Cheng, Ruoyu; Sun, Zhiyong; Su, Wei; Pan, Guoqing; Zhao, Song; Zhao, Jinzhong; Cui, Wenguo

    2017-10-01

    Enthesis is a specialized tissue interface between the tendon and bone. Enthesis structure is very complex because of gradient changes in its composition and structure. There is currently no strategy to create a suitable environment and to regenerate the gradual-changing enthesis because of the modular complexities between two tissue types. Herein, a dual-layer organic/inorganic flexible bipolar fibrous membrane (BFM) was successfully fabricated by electrospinning to generate biomimetic non-mineralized fibrocartilage and mineralized fibrocartilage in tendon-to-bone integration of enthesis. The growth of the in situ apatite nanoparticle layer was induced on the nano hydroxyapatite-poly-l-lactic acid (nHA-PLLA) fibrous layer in simulated body solution, and the poly-l-lactic acid (PLLA) fibrous layer retained its original properties to induce tendon regeneration. The in vivo results showed that BFM significantly increased the area of glycosaminoglycan staining at the tendon-bone interface and improved collagen organization when compared to the simplex fibrous membrane (SFM) of PLLA. Implanting the bipolar membrane also induced bone formation and fibrillogenesis as assessed by micro-CT and histological analysis. Biomechanical testing showed that the BFM group had a greater ultimate load-to-failure and stiffness than the SFM group at 12weeks after surgery. Therefore, this flexible bipolar nanofibrous membrane improves the healing and regeneration process of the enthesis in rotator cuff repair. In this study, we generated a biomimetic dual-layer organic/inorganic flexible bipolar fibrous membrane by sequential electrospinning and in situ biomineralization, producing integrated bipolar fibrous membranes of PLLA fibrous membrane as the upper layer and nHA-PLLA fibrous membrane as the lower layer to mimic non-mineralized fibrocartilage and mineralized fibrocartilage in tendon-to-bone integration of enthesis. Flexible bipolar nanofibrous membranes could be easily fabricated

  11. Effect of eccentric training on the plantar flexor muscle-tendon tissue properties.

    Science.gov (United States)

    Mahieu, Nele Nathalie; McNair, Peter; Cools, Ann; D'Haen, Caroline; Vandermeulen, Katrien; Witvrouw, Erik

    2008-01-01

    It has been shown that eccentric training can be effective in the rehabilitation of patients with Achilles tendonopathy. The mechanism behind these results is not clear. However, there is evidence that tendons are able to respond to repeated forces by altering their structure and composition, and, thus, their mechanical properties change. In this regard, the objective of the present study was to investigate whether eccentric training affects the mechanical properties of the plantar flexor's muscle-tendon tissue properties. Seventy-four healthy subjects were randomized into two groups: an eccentric training group and a control group. The eccentric training group performed a 6-wk eccentric training program for the calf muscles. Before and after this period, all subjects were evaluated for dorsiflexion range of motion using universal goniometry, passive resistive torque of the plantar flexors, and stiffness of the Achilles tendon. Passive resistive torque was measured during ankle dorsiflexion on an isokinetic dynamometer. Stiffness of the Achilles tendon was assessed using a dynamometer, in combination with ultrasonography. The results of the study reveal that the dorsiflexion range of motion was significantly increased only in the eccentric training group. The eccentric heel drop program also resulted in a significant decrease of the passive resistive torque of the plantar flexors (from 16.423 +/- 0.827 to 12.651 +/- 0.617 N.m). The stiffness of the Achilles tendon did not change significantly as a result of training. These findings provide evidence that an eccentric training program results in changes to some of the mechanical properties of the plantar flexor muscles. These changes were thought to be associated with modifications to structure rather than to stretch tolerance.

  12. An artificial tendon with durable muscle interface.

    Science.gov (United States)

    Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

    2010-02-01

    A coupling mechanism that can permanently fix a forcefully contracting muscle to a bone anchor or any totally inert prosthesis would meet a serious need in orthopaedics. Our group developed the OrthoCoupler device to satisfy these demands. The objective of this study was to test OrthoCoupler's performance in vitro and in vivo in the goat semitendinosus tendon model. For in vitro evaluation, 40 samples were fatigue-tested, cycling at 10 load levels, n = 4 each. For in vivo evaluation, the semitendinosus tendon was removed bilaterally in eight goats. Left sides were reattached with an OrthoCoupler, and right sides were reattached using the Krackow stitch with #5 braided polyester sutures. Specimens were harvested 60 days postsurgery and assigned for biomechanics and histology. Fatigue strength of the devices in vitro was several times the contractile force of the semitendinosus muscle. The in vivo devices were built equivalent to two of the in vitro devices, providing an additional safety factor. In strength testing at necropsy, suture controls pulled out at 120.5 +/- 68.3 N, whereas each OrthoCoupler was still holding after the muscle tore, remotely, at 298 +/- 111.3 N (mean +/- SD) (p < 0.0003). Muscle tear strength was reached with the fiber-muscle composite produced in healing still soundly intact. This technology may be of value for orthopaedic challenges in oncology, revision arthroplasty, tendon transfer, and sports-injury reconstruction. (c) 2009 Orthopaedic Research Society.

  13. A group of patients with Marfan's syndrome, who have finger and toe contractures, displays tendons' alterations upon an ultrasound examination: are these features common among classical Marfan patients?

    Science.gov (United States)

    Melchiorre, Daniela; Pratelli, Elisa; Torricelli, Elena; Sofi, Francesco; Abbate, Rosanna; Matucci-Cerinic, Marco; Gensini, GianFranco; Pepe, Guglielmina

    2016-08-01

    The involvement of the musculoskeletal system with other mild pleiotropic manifestations represents a clinical criterion, called "systemic features," to d iagnose Marfan's syndrome. We aimed to investigate the features of the hands and feet redressable contractures present in a group of Marfan patients. In 13 patients with previously diagnosed Marfan's syndrome, an accurate clinical examination was performed. In particular the characterization of the musculoskeletal system by visual analogic scale to measure muscle pain (VAS) and muscle strength (MRC system) was carried out; the Beighton scale score was used to evaluate the articular hypermobility. Ultrasound examination (US) was performed to detect deep-superficial flexor tendons and extensor tendons of both hands, and the short and long flexor and extensor tendons of the fingers and toes in static and dynamic positions. The ImageJ program was adopted to measure a profile of tendon echo-intensity. A reduction of the thickness of all tendons was detected by US in our patients; the VAS and Beighton scale scores were in normal ranges. The profile of tendon echo-intensity showed different textural details in all Marfan patients. This study provides evidence for other contractures' localization, and for altered findings of the tendons in patients with Marfan syndrome and finger/toe contractures. These changes may be associated with structural modifications in connective tissue.

  14. Arthroscopically-Asissted Achilles Tendon Repair; Long-Term Results

    OpenAIRE

    Turgut, Ak?n; Asfuro?lu, Mert Zeynel

    2014-01-01

    Objectives: The ruptures of the Achilles tendon (AT) are relatively common. Since there is no consensus on the best method of the repair of the AT; the treatment is determined on the preference of the surgeon and the patient. The study evaluating the cadaveric and short term clinical results done by our clinic in 2002, has shown us that arthroscopically Achilles tendon repair can be good choise in achilles tendon ruptures. Methods: Fortyfour patients who underwent arthroscopically assisted ac...

  15. Reconstruction of Ligament and Tendon Defects Using Cell Technologies.

    Science.gov (United States)

    Chailakhyan, R K; Shekhter, A B; Ivannikov, S V; Tel'pukhov, V I; Suslin, D S; Gerasimov, Yu V; Tonenkov, A M; Grosheva, A G; Panyushkin, P V; Moskvina, I L; Vorob'eva, N N; Bagratashvili, V N

    2017-02-01

    We studied the possibility of restoring the integrity of the Achilles tendon in rabbits using autologous multipotent stromal cells. Collagen or gelatin sponges populated with cells were placed in a resorbable Vicryl mesh tube and this tissue-engineered construct was introduced into a defect of the middle part of the Achilles tendon. In 4 months, histological analysis showed complete regeneration of the tendon with the formation of parallel collagen fibers, spindle-shaped tenocytes, and newly formed vessels.

  16. Contrast material filling of the peroneal tendon sheath

    International Nuclear Information System (INIS)

    Zadravecz, Gy.; Grexa, E.

    1981-01-01

    In case of complaints after fracture of the calcaneus the common sheath of the peroneus tendons was filled up with contrast material. The tendon sheath was punctured Oehind the external ankle. The three-directional radiograms clearly showed the dislocation and compression of the tendons, caused by the exostosis of the calcaneus. The concomitant tendovaginitis caused the complaints. This alteration was observed in 11% of all the calcaneus fractures. (L.E.)

  17. Ultrasound Characteristics of the Achilles Tendon in Tophaceous Gout: A Comparison with Age- and Sex-matched Controls.

    Science.gov (United States)

    Carroll, Matthew; Dalbeth, Nicola; Allen, Bruce; Stewart, Sarah; House, Tony; Boocock, Mark; Frampton, Christopher; Rome, Keith

    2017-10-01

    To investigate the frequency and distribution of characteristics of the Achilles tendon (AT) in people with tophaceous gout using musculoskeletal ultrasound (US). Twenty-four participants with tophaceous gout and 24 age- and sex-matched controls without gout or other arthritis were recruited. All participants underwent a greyscale and power Doppler US examination. The AT was divided into 3 anatomical zones (insertion, pre-insertional, and proximal to the mid-section). The following US characteristics were assessed: tophus, tendon echogenicity, tendon vascularity, tendon morphology, entheseal characteristics, bursal morphology, and calcaneal bone profile. The majority of the participants with tophaceous gout were middle-aged men (n = 22, 92%) predominately of European ethnicity (n = 14, 58%). Tophus deposition was observed in 73% (n = 35) of tendons in those with gout and in none of the controls (p gout compared to controls. High prevalence of entheseal calcifications, calcaneal bone cortex irregularities, and calcaneal enthesophytes were observed in both gout participants and controls, without differences between groups. Intratendinous structural damage was rare. Hyperechoic spots were significantly more common at the insertion compared to the zone proximal to the mid-section (p gout. Despite crystal deposition, intratendinous structural changes are infrequent. Many characteristics observed in the AT in people with tophaceous gout, particularly at the calcaneal enthesis, are not disease-specific.

  18. Nanoparticles for tendon healing and regeneration: literature review.

    Directory of Open Access Journals (Sweden)

    Paolo Domenico Parchi

    2016-08-01

    Full Text Available Tendon injuries are commonly met in the emergency department. Unfortunately, tendon tissue has limited regeneration potential and usually the consequent formation of scar tissue causes inferior mechanical properties Nanoparticles could be used in different way to improve tendon healing and regeneration, ranging from scaffolds manufacturing (increasing the strength and endurance or anti-adhesions, anti-microbial and anti-inflammatory properties to gene therapy. This paper aims to summarize the most relevant studies showing the potential application of nanoparticles for tendon tissue regeneration

  19. Magnetic resonance imaging and computed radiography in Achilles tendon rupture

    International Nuclear Information System (INIS)

    Korenaga, Tateo; Hachiya, Junichi; Miyasaka, Yasuo

    1988-01-01

    Magnetic Resonance Imaging (MRI) and Computed Radiography (CR) were performed in 15 patients with complete Achilles tendon rupture who were treated conservatively without surgery. MRI was obtained using Toshiba MRT 50 A superconductive machine, operaing at 0.5 Tesla. CR was performed by CR-101, Fuji Medical System. In fresh cases, ruptured tendons showed intermediate signal intensity on T1-weighted images and high intensity on T2-weighted images. Thickening of the tendon was observed in all cases except in very acute stage. Configuration of thickend tendons tends to be dumbbell shape in subacute stage and fusiform in chronic stage of more than six months after the initial trauma. In cases which showed high signal intensity at the ruptured area both on T1 and T2 weighted images, migration of fat into the sapces between the ruptured tendons was considered to be the major source of increased signal intensity. Computed radiography showed thickening of the tendon, blurring of anterior margin of the tendon, and decreased translucency of pre-Achilles fat pad. However, MRI better demonstrated the details of ruptured tendons when compared to CR, and thought to be an usefull way of following up the healing process of the ruptured tendon to facilitate more reasonable judgement of the time of removing plaster casts and stating exercise. (author)

  20. Ossification of the bilateral Achilles tendon: a rare entity

    International Nuclear Information System (INIS)

    Arora, Abhishek J; Arora, Richa

    2015-01-01

    Ossification of the Achilles tendon is a rare clinical entity comprising of one or more segments of variable sized ossified masses in the fibrocartilaginous substance of the tendon. The etiology of ossification of the Achilles tendon is multifactorial with recurrent trauma and surgery comprising major predisposing factors, with others being metabolic, systemic, and infectious diseases. The possibility of a genetic predisposition towards this entity has also been raised, but has not yet been proven. We present a rare case of ossification of the bilateral Achilles tendons without any history of trauma or surgery in a 48-year-old female patient

  1. Biology and augmentation of tendon-bone insertion repair

    Directory of Open Access Journals (Sweden)

    Lui PPY

    2010-08-01

    Full Text Available Abstract Surgical reattachment of tendon and bone such as in rotator cuff repair, patellar-patella tendon repair and anterior cruciate ligament (ACL reconstruction often fails due to the failure of regeneration of the specialized tissue ("enthesis" which connects tendon to bone. Tendon-to-bone healing taking place between inhomogenous tissues is a slow process compared to healing within homogenous tissue, such as tendon to tendon or bone to bone healing. Therefore special attention must be paid to augment tendon to bone insertion (TBI healing. Apart from surgical fixation, biological and biophysical interventions have been studied aiming at regeneration of TBI healing complex, especially the regeneration of interpositioned fibrocartilage and new bone at the healing junction. This paper described the biology and the factors influencing TBI healing using patella-patellar tendon (PPT healing and tendon graft to bone tunnel healing in ACL reconstruction as examples. Recent development in the improvement of TBI healing and directions for future studies were also reviewed and discussed.

  2. Vascular abnormalities of the distal deep digital flexor tendon in 8 draught horses identified on histological examination.

    Science.gov (United States)

    Crişan, Melania Ioana; Damian, Aurel; Gal, Adrian; Miclăuş, Viorel; Cernea, Cristina L; Denoix, Jean-Marie

    2013-08-01

    The purpose of this study was to provide a detailed description of the vascular changes in the distal part of deep digital flexor tendon (DDFT). Eight isolated forelimbs were collected from 8 horses with DDF tendinopathy diagnosed post-mortem by ultrasound and gross anatomopathological examination. The samples were fixed in 10% neutral buffered formalin, softened in 4% phenol and dehydrated with ethylic alcohol. Goldner's Trichrome staining method was used. The histopathological examination revealed vascular proliferation associated with structural disorders of blood vessels. Angiogenesis, fibroplasia and consecutive hypertrophy of the vascular wall with or without vascular occlusion were the most common findings. Other histopathological findings were: endothelial cell edema, progressive metaplasia from squamous to cubic cells, vascular wall hyalinization, endothelial cells apoptosis/necrosis and endothelial desquamation. These results demonstrated damage of the distal deep digital flexor tendon vasculature which may progressively alter the structural integrity of the tendon and contribute to degenerative lesions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Increased supraspinatus tendon thickness following fatigue loading in rotator cuff tendinopathy: potential implications for exercise therapy

    OpenAIRE

    McCreesh, Karen M; Purtill, Helen; Donnelly, Alan E; Lewis, Jeremy S

    2017-01-01

    Background/aim Exercise imparts a load on tendon tissue that leads to changes in tendon properties. Studies suggest that loading immediately reduces tendon thickness, with a loss of this response in symptomatic tendinopathy. No studies investigating the response of tendon dimensions to load for the rotator cuff tendons exist. This study aimed to examine the short-term effect of loading on the thickness of the supraspinatus tendon and acromiohumeral distance those with and without rotator cuff...

  4. Role of tissue-engineered artificial tendon in healing of a large Achilles tendon defect model in rabbits.

    Science.gov (United States)

    Moshiri, Ali; Oryan, Ahmad; Meimandi-Parizi, Abdolhamid

    2013-09-01

    Treatment of large Achilles tendon defects is technically demanding. Tissue engineering is an option. We constructed a collagen-based artificial tendon, covered it with a polydioxanon (PDS) sheath, and studied the role of this bioimplant on experimental tendon healing in vivo. A 2-cm tendon gap was created in the left Achilles tendon of rabbits (n = 120). The animals were randomly divided into 3 groups: control (no implant), treated with tridimensional-collagen, and treated with tridimensional-collagen-bidimensional-PDS implants. Each group was divided into 2 subgroups of 60 and 120 days postinjury (DPI). Another 50 pilot animals were used to study the host-implant interaction. Physical activity of the animals was scored and ultrasonographic and bioelectrical characteristics of the injured tendons were investigated weekly. After euthanasia, macro, micro, and nano morphologies and biophysical and biomechanical characteristics of the healing tendons were studied. Treatment improved function of the animals, time dependently. At 60 and 120 DPI, the treated tendons showed significantly higher maximum load, yield, stiffness, stress, and modulus of elasticity compared with controls. The collagen implant induced inflammation and absorbed the migrating fibroblasts in the defect area. By its unique architecture, it aligned the fibroblasts and guided their proliferation and collagen deposition along the stress line of the tendon and resulted in improved collagen density, micro-amp, micro-ohm, water uptake, and delivery of the regenerated tissue. The PDS-sheath covering amplified these characteristics. The implants were gradually absorbed and replaced by a new tendon. Minimum amounts of peritendinous adhesion, muscle atrophy, and fibrosis were observed in the treated groups. Some remnants of the implants were preserved and accepted as a part of the new tendon. The implants were cytocompatible, biocompatible, biodegradable, and effective in tendon healing and regeneration. This

  5. Knitted poly-lactide-co-glycolide scaffold loaded with bone marrow stromal cells in repair and regeneration of rabbit Achilles tendon.

    Science.gov (United States)

    Ouyang, Hong Wei; Goh, James C H; Thambyah, Ashvin; Teoh, Swee Hin; Lee, Eng Hin

    2003-06-01

    The objectives of this study were to evaluate the morphology and biomechanical function of Achilles tendons regenerated using knitted poly-lactide-co-glycolide (PLGA) loaded with bone marrow stromal cells (bMSCs). The animal model used was that of an adult female New Zealand White rabbit with a 10-mm gap defect of the Achilles tendon. In group I, 19 hind legs with the created defects were treated with allogeneic bMSCs seeded on knitted PLGA scaffold. In group II, the Achilles tendon defects in 19 hind legs were repaired using the knitted PLGA scaffold alone, and in group III, 6 hind legs were used as normal control. The tendon-implant constructs of groups I and II were evaluated postoperatively at 2, 4, 8, and 12 weeks using macroscopic, histological, and immunohistochemical techniques. In addition, specimens from group I (n = 7), group II (n = 7), and group III (n = 6) were harvested for biomechanical test 12 weeks after surgery. Postoperatively, at 2 and 4 weeks, the histology of group I specimens exhibited a higher rate of tissue formation and remodeling as compared with group II, whereas at 8 and 12 weeks postoperation, the histology of both group I and group II was similar to that of native tendon tissue. The wound sites of group I healed well and there was no apparent lymphocyte infiltration. Immunohistochemical analysis showed that the regenerated tendons were composed of collagen types I and type III fibers. The tensile stiffness and modulus of group I were 87 and 62.6% of normal tendon, respectively, whereas those of group II were about 56.4 and 52.9% of normal tendon, respectively. These results suggest that the knitted PLGA biodegradable scaffold loaded with allogeneic bone marrow stromal cells has the potential to regenerate and repair gap defect of Achilles tendon and to effectively restore structure and function.

  6. The Effect of Phospholipids (Surfactant on Adhesion and Biomechanical Properties of Tendon: A Rat Achilles Tendon Repair Model

    Directory of Open Access Journals (Sweden)

    T. Kursat Dabak

    2015-01-01

    Full Text Available Adhesion of the tendon is a major challenge for the orthopedic surgeon during tendon repair. Manipulation of biological environment is one of the concepts to prevent adhesion. Lots of biochemicals have been studied for this purpose. We aimed to determine the effect of phospholipids on adhesion and biomechanical properties of tendon in an animal tendon repair model. Seventy-two Wistar rats were divided into 4 groups. Achilles tendons of rats were cut and repaired. Phospholipids were applied at two different dosages. Tendon adhesion was determined histopathologically and biomechanical test was performed. At macroscopic evaluation of adhesion, there are statistically significant differences between multiple-dose phospholipid injection group and Control group and also hyaluronic acid group and Control group (p0.008. Ultimate strength was highest at hyaluronic acid injection group and lowest at multiple-dose phospholipid injection group. Single-dose phospholipids (surfactant application may have a beneficial effect on the tendon adhesion. Although multiple applications of phospholipids seem the most effective regime to reduce the tendon adhesion among groups, it deteriorated the biomechanical properties of tendon.

  7. Science to Practice: Quantitative US Elastography Can Be Used to Quantify Mechanical and Histologic Tendon Healing in a Rabbit Model of Achilles Tendon Transection.

    Science.gov (United States)

    Lee, Kenneth S; Martin, Jack; Thelen, Darryl

    2017-05-01

    Compression-based ultrasonographic (US) elastography is associated with time-dependent mechanical and histologic changes of the healing tendon in a transected rabbit model of the Achilles tendon. This finding will lead to continued development of quantitative US, which can be used to objectively assess a diseased or healing tendon. With advances in the method used, clinical translation of tendon elastography may enable clinicians to diagnose tendon damage and track healing, which should improve both treatment and outcome.

  8. Achilles tendon injuries in elite athletes: lessons in pathophysiology from their equine counterparts.

    Science.gov (United States)

    Patterson-Kane, Janet C; Rich, Tina

    2014-01-01

    Superficial digital flexor tendon (SDFT) injury in equine athletes is one of the most well-accepted, scientifically supported companion animal models of human disease (i.e., exercise-induced Achilles tendon [AT] injury). The SDFT and AT are functionally and clinically equivalent (and important) energy-storing structures for which no equally appropriate rodent, rabbit, or other analogues exist. Access to equine tissues has facilitated significant advances in knowledge of tendon maturation and aging, determination of specific exercise effects (including early life), and definition of some of the earliest stages of subclinical pathology. Access to human surgical biopsies has provided complementary information on more advanced phases of disease. Importantly, equine SDFT injuries are only a model for acute ruptures in athletes, not the entire spectrum of human tendonopathy (including chronic tendon pain). In both, pathology begins with a potentially prolonged phase of accumulation of (subclinical) microdamage. Recent work has revealed remarkably similar genetic risk factors, including further evidence that tenocyte dysfunction plays an active role. Mice are convenient but not necessarily accurate models for multiple diseases, particularly at the cellular level. Mechanistic studies, including tendon cell responses to combinations of exercise-associated stresses, require a more thorough investigation of cross-species conservation of key stress pathway auditors. Molecular evidence has provided some context for the poor performance of mouse models; equines may provide better systems at this level. The use of horses may be additionally justifiable based on comparable species longevity, lifestyle factors, and selection pressure by similar infectious agents (e.g., herpesviruses) on general cell stress pathway evolution. © The Author 2014. Published by Oxford University Press on behalf of the Institute for Laboratory Animal Research. All rights reserved. For permissions

  9. Ovine tendon collagen: Extraction, characterisation and fabrication of thin films for tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Fauzi, M.B.; Lokanathan, Y. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Aminuddin, B.S. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Ear, Nose & Throat Consultant Clinic, Ampang Puteri Specialist Hospital, Taman Dato Ahmad Razali, 68000 Ampang, Selangor (Malaysia); Ruszymah, B.H.I. [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Department of Physiology, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia); Chowdhury, S.R., E-mail: shiplu@ppukm.ukm.edu.my [Tissue Engineering Centre, UKM Medical Centre, Jalan Yaacob Latiff, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur (Malaysia)

    2016-11-01

    Collagen is the most abundant extracellular matrix (ECM) protein in the human body, thus widely used in tissue engineering and subsequent clinical applications. This study aimed to extract collagen from ovine (Ovis aries) Achilles tendon (OTC), and to evaluate its physicochemical properties and its potential to fabricate thin film with collagen fibrils in a random or aligned orientation. Acid-solubilized protein was extracted from ovine Achilles tendon using 0.35 M acetic acid, and 80% of extracted protein was measured as collagen. SDS-PAGE and mass spectrometry analysis revealed the presence of alpha 1 and alpha 2 chain of collagen type I (col I). Further analysis with Fourier transform infrared spectrometry (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) confirms the presence of triple helix structure of col I, similar to commercially available rat tail col I. Drying the OTC solution at 37°C resulted in formation of a thin film with randomly orientated collagen fibrils (random collagen film; RCF). Introduction of unidirectional mechanical intervention using a platform rocker prior to drying facilitated the fabrication of a film with aligned orientation of collagen fibril (aligned collagen film; ACF). It was shown that both RCF and ACF significantly enhanced human dermal fibroblast (HDF) attachment and proliferation than that on plastic surface. Moreover, cells were distributed randomly on RCF, but aligned with the direction of mechanical intervention on ACF. In conclusion, ovine tendon could be an alternative source of col I to fabricate scaffold for tissue engineering applications. - Highlights: • Isolated collagen from ovine tendon was characterized as collagen type I. • Collagen film was fabricated via air drying of ovine tendon collagen. • Collagen fibril alignment was realized via unidirectional platform rocker. • Orientation of cells was attained depending on collagen fibril direction in the film. • Collagen films

  10. Measurement of stress strain and vibrational properties of tendons

    Science.gov (United States)

    Revel, Gian Marco; Scalise, Alessandro; Scalise, Lorenzo

    2003-08-01

    The authors present a new non-intrusive experimental procedure based on laser techniques for the measurement of mechanical properties of tendons. The procedure is based on the measurement of the first resonance frequency of the tendon by laser Doppler vibrometry during in vitro tensile experiments, with the final aim of establishing a measurement procedure to perform the mechanical characterization of tendons by extracting parameters such as the resonance frequency, also achievable during in vivo investigation. The experimental procedure is reported, taking into account the need to simulate the physiological conditions of the Achilles tendon, and the measurement technique used for the non-invasive determination of tendon cross-sectional area during tensile vibration tests at different load levels is described. The test procedure is based on a tensile machine, which measures longitudinal tendons undergoing controlled load conditions. Cross-sectional area is measured using a new non-contact procedure for the measurement of tendon perimeter (repeatability of 99% and accuracy of 2%). For each loading condition, vibration resonance frequency and damping, cross-sectional area and tensile force are measured, allowing thus a mechanical characterization of the tendon. Tendon stress-strain curves are reported. Stress-strain curves have been correlated to the first vibration resonance frequency and damping of the tendon measured using a single-point laser Doppler vibrometer. Moreover, experimental results have been compared with a theoretical model of a vibrating cord showing discrepancies. In vitro tests are reported, demonstrating the validity of the method for the comparison of different aged rabbit tendons.

  11. The Relation between Calcium Supplement Consumption and Calcific Shoulder Tendonitis

    Directory of Open Access Journals (Sweden)

    Alireza Rouhani

    2015-10-01

    Full Text Available Background: Calcific tendonitis is a common cause of non-traumatic shoulder pain. Previous studies have suggested a relation between minerals and endocrine and calcium deposition. Thus, hypercalcemia is probably related to calcific tendonitis. This study aims at evaluating the relation found between calcium supplement consumption and calcific shoulder tendonitis. Methods: This analytical-descriptive study was conducted on 250 patients with shoulder pain referring to clinics and emergency department of Shohada Orthopedics Hospital during one year for considering calcific shoulder tendonitis and calcium supplement consumption. Patients with calcific tendonitis were treated and their functional ability was evaluated using DASH questionnaire, pain severity and range of motion (ROM before and after treatment and their correlation with calcium supplement consumption. Results: Calcific tendonitis and calcium consumption were generally seen in 30 (12% and 73 (29.2% cases, respectively. Calcium consumption frequency in patients with calcific tendonitis was significantly higher than the patients who did not consume calcium supplements (76.7% vs. 22.7%. Patients with calcific tendonitis who did not consume calcium supplements suffered from significantly longer periods of shoulder pain. All patients having consumed calcium supplement were female. The group who consumed calcium supplement had significantly severe pain and higher DASH score before and after treatment, while there was no significant difference in number of impaired ROM before and after treatment. Also, there was a negative correlation between calcium supplement consumption, pain severity and DASH score before and after treatment. Conclusion: Calcium supplement consumption is related to calcific tendonitis and is also accompanied with more pain and lower functional ability in patients with calcific tendonitis.    Keywords: Calcific tendonitis; Shoulder; Calcium supplement; Pain

  12. A role for hedgehog signaling in the differentiation of the insertion site of the patellar tendon in the mouse.

    Directory of Open Access Journals (Sweden)

    Chia-Feng Liu

    Full Text Available Tendons are typically composed of two histologically different regions: the midsubstance and insertion site. We previously showed that Gli1, a downstream effector of the hedgehog (Hh signaling pathway, is expressed only in the insertion site of the mouse patellar tendon during its differentiation. To test for a functional role of Hh signaling, we targeted the Smoothened (Smo gene in vivo using a Cre/Lox system. Constitutive activation of the Hh pathway in the mid-substance caused molecular markers of the insertion site, e.g. type II collagen, to be ectopically expressed or up-regulated in the midsubstance. This was confirmed using a novel organ culture method in vitro. Conversely, when Smo was excised in the scleraxis-positive cell population, the development of the fibrocartilaginous insertion site was affected. Whole transcriptome analysis revealed that the expression of genes involved in chondrogenesis and mineralization was down-regulated in the insertion site, and expression of insertion site markers was decreased. Biomechanical testing of murine adult patellar tendon, which developed in the absence of Hh signaling, showed impairment of tendon structural properties (lower linear stiffness and greater displacement and material properties (greater strain, although the linear modulus of the mutant group was not significantly lower than controls. These studies provide new insights into the role of Hh signaling during tendon development.

  13. In vitro and in vivo effects of PDGF-BB delivery strategies on tendon healing: a review

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    O Evrova

    2017-07-01

    Full Text Available To promote and support tendon healing, one viable strategy is the use or administration of growth factors at the wound/rupture site. Platelet derived growth factor-BB (PDGF-BB, together with other growth factors, is secreted by platelets after injury. PDGF-BB promotes mitogenesis and angiogenesis, which could accelerate tendon healing. Therefore, in vitro studies with PDGF-BB have been performed to determine its effect on tenocytes and tenoblasts. Moreover, accurate and sophisticated drug delivery devices, aiming for a sustained release of PDGF-BB, have been developed, either by using heparin-binding and fibrin-based matrices or different electrospinning techniques. In this review, the structure and composition, as well as the healing process of tendons, are described. Part A deals with in vitro studies. They focus on the multiple effects evoked by PDGF-BB on the cellular level. Moreover, they address strategies for the sustained delivery of PDGF-BB. Part B focuses on animal models used to test different delivery strategies for PDGF-BB, in the context of tendon reconstruction. These studies showed that dosage and timing of PDGF-BB application are the most important factors for deciding which delivery device should be applied for a specific tendon laceration.

  14. Step Cut Lengthening: A Technique for Treatment of Flexor Pollicis Longus Tendon Rupture.

    Science.gov (United States)

    Chong, Chew-Wei; Chen, Shih-Heng

    2018-04-01

    Reconstruction of a tendon defect is a challenging task in hand surgery. Delayed repair of a ruptured flexor pollicis longus (FPL) tendon is often associated with tendon defect. Primary repair of the tendon is often not possible, particularly after debridement of the unhealthy segment of the tendon. As such, various surgical treatments have been described in the literature, including single-stage tendon grafting, 2-stage tendon grafting, flexor digitorum superficialis tendon transfer from ring finger, and interphalangeal joint arthrodesis. We describe step cut lengthening of FPL tendon for the reconstruction of FPL rupture. This is a single-stage reconstruction without the need for tendon grafting or tendon transfer. To our knowledge, no such technique has been previously described.

  15. Semitendinosus Tendon for Solitary Use in Anterior Cruciate ...

    African Journals Online (AJOL)

    The ANNALS of AFRICAN SURGERY | www.annalsofafricansurgery.com. The ANNALS of ... knee instability. Tendon allografts and autografts have been used successfully to reconstruct a torn. ACL. However, allografts have been associated with a higher rate of failure .... Semitendinosus Tendon to Prevent a. Postoperative ...

  16. Tendinography for diagnosing injuries to tendons and ligaments

    International Nuclear Information System (INIS)

    Grevsten, S.; Eriksson, K.

    1979-01-01

    A radiographic method of tendinography is described. In rabbits no inflammatory reaction in the Achilles tendon was observed 12 to 15 days after injection of contrast medium. Effects of examination of two healthy subjects and a patient with a traumatic condition are described. Suitable amounts and concentrations of contrast medium for examinations of Achilies tendon and cruciate ligaments are discussed. (Auth.)

  17. Rehabilitation of tendon problems in patients with diabetes mellitus

    NARCIS (Netherlands)

    Rees, Jonathan; Gaida, Jamie E.; Silbernagel, Karin Grävare; Zwerver, Johannes; Anthony, Joseph S.; Scott, Alex; Ackermann, PW; Hart, DA

    2016-01-01

    Exercise is crucial in the management of diabetes mellitus and its associated complications. However, individuals with diabetes have a heightened risk of musculoskeletal problems, including tendon pathologies. Diabetes has a significant impact on the function of tendons due to the accumulation of

  18. Open extensor tendon injuries: an epidemiologic study.

    Science.gov (United States)

    Patillo, Dominic; Rayan, Ghazi M

    2012-01-01

    To report the epidemiology, mechanism, anatomical location, distribution, and severity of open extensor tendon injuries in the digits, hand, and forearm as well as the frequency of associated injuries to surrounding bone and soft tissue. Retrospective chart review was conducted for patients who had operative repair of open digital extensor tendon injuries in all zones within an 11-year period. Data was grouped according to patient characteristics, zone of injury, mechanism of injury, and presence of associated injury. Statistical analysis was used to determine the presence of relevant associations. Eighty-six patients with 125 severed tendons and 105 injured digits were available for chart reviews. Patients were predominantly males (83%) with a mean age of 34.2 years and the dominant extremity was most often injured (60%). The thumb was the most commonly injured (25.7%), followed by middle finger (24.8), whereas small finger was least affected (10.5%). Sharp laceration was the most common mechanism of injury (60%), and most of these occurred at or proximal to the metacarpophalangeal joints. Most saw injuries occurred distal to the metacarpophalangeal joint. Zone V was the most commonly affected in the fingers (27%) while zone VT was the most commonly affected in the thumb (69%). Associated injuries to bone and soft tissue occurred in 46.7% of all injuries with saw and crush/avulsions being predictive of fractures and damage to the underlying joint capsule. The extensor mechanism is anatomically complex, and open injuries to the dorsum of the hand, wrist, and forearm, especially of crushing nature and those inflicted by saws, must be thoroughly evaluated. Associated injuries should be ruled out in order to customize surgical treatment and optimize outcome.

  19. Pain level after ACL reconstruction: A comparative study between free quadriceps tendon and hamstring tendons autografts.

    Science.gov (United States)

    Buescu, Cristian Tudor; Onutu, Adela Hilda; Lucaciu, Dan Osvald; Todor, Adrian

    2017-03-01

    The objective of this study was to compare the pain levels and analgesic consumption after single bundle ACL reconstruction with free quadriceps tendon autograft versus hamstring tendon autograft. A total of 48 patients scheduled for anatomic single-bundle ACL reconstruction were randomized into two groups: the free quadriceps tendon autograft group (24 patients) and the hamstring tendons autograft group (24 patients). A basic multimodal analgesic postoperative program was used for all patients and rescue analgesia was provided with tramadol, at pain scores over 30 on the Visual Analog Scale. The time to the first rescue analgesic, the number of doses of tramadol and pain scores were recorded. The results within the same group were compared with the Wilcoxon signed test. Supplementary analgesic drug administration proved significantly higher in the group of subjects with hamstring grafts, with a median (interquartile range) of 1 (1.3) dose, compared to the group of subjects treated with a quadriceps graft, median = 0.5 (0.1.25) (p = 0.009). A significantly higher number of subjects with a quadriceps graft did not require any supplementary analgesic drug (50%) as compared with subjects with hamstring graft (13%; Z-statistics = 3.01, p = 0.002). The percentage of subjects who required a supplementary analgesic drug was 38% higher in the HT group compared with the FQT group. The use of the free quadriceps tendon autograft for ACL reconstruction leads to less pain and analgesic consumption in the immediate postoperative period compared with the use of hamstrings autograft. Level I Therapeutic study. Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  20. An Artificial Tendon with Durable Muscle Interface

    OpenAIRE

    Melvin, Alan; Litsky, Alan; Mayerson, Joel; Witte, David; Melvin, David; Juncosa-Melvin, Natalia

    2010-01-01

    A coupling mechanism that can permanently fix a forcefully contracting muscle to a bone anchor or any totally inert prosthesis would meet a serious need in orthopaedics. Our group developed the OrthoCoupler™ device to satisfy these demands. The objective of this study was to test OrthoCoupler’s performance in vitro and in vivo in the goat semitendinosus tendon model. For in vitro evaluation, 40 samples were fatigue-tested, cycling at 10 load levels, n=4 each. For in vivo evaluation, the semit...

  1. Torque Control of Underactuated Tendon-driven Robotic Fingers

    Science.gov (United States)

    Abdallah, Muhammad E. (Inventor); Ihrke, Chris A. (Inventor); Reiland, Matthew J. (Inventor); Wampler, Charles W. (Inventor); Diftler, Myron A. (Inventor); Platt, Robert (Inventor); Bridgwater, Lyndon (Inventor)

    2013-01-01

    A robotic system includes a robot having a total number of degrees of freedom (DOF) equal to at least n, an underactuated tendon-driven finger driven by n tendons and n DOF, the finger having at least two joints, being characterized by an asymmetrical joint radius in one embodiment. A controller is in communication with the robot, and controls actuation of the tendon-driven finger using force control. Operating the finger with force control on the tendons, rather than position control, eliminates the unconstrained slack-space that would have otherwise existed. The controller may utilize the asymmetrical joint radii to independently command joint torques. A method of controlling the finger includes commanding either independent or parameterized joint torques to the controller to actuate the fingers via force control on the tendons.

  2. Final report on PCRV thermal cylinder axial tendon failures

    International Nuclear Information System (INIS)

    Canonico, D.A.; Griess, J.C.; Robinson, G.C.

    1976-01-01

    The post-test examination of the failed tendons from the PCRV thermal cylinder experiment has been concluded. Failures in the wires are attributed to stress-corrosion cracking. The cause of tendon failures has not been unequivocably established, but they may have been due to nitrates in the duct. The wires employed in the manufacture of the tendons will crack in less than 72 hr in a 0.2 M solution of ammonium nitrate at 70 0 C. The quality of the wires is poor, and surface cracks were detected. These could have acted as concentrating sites for both stress and the deleterious contaminants. It is believed that the factors that led to the failures in the thermal cylinder experiment were unique. An improper formulation of the epoxy resin did not provide the tendon anchor plate seal that was desired; indeed, the improper formulation is responsible for the high level of nitrogen in the ducts of the failed tendons

  3. Nonoperative, dynamic treatment of acute achilles tendon rupture

    DEFF Research Database (Denmark)

    Barfod, Kristoffer Weisskirchner; Bencke, Jesper; Lauridsen, Hanne Bloch

    2015-01-01

    Acute Achilles tendon rupture alters the biomechanical properties of the plantar flexor muscle-tendon complex that can affect functional performance and the risk of repeat injury. The purpose of the present study was to compare the biomechanical properties of the plantar flexor muscle-tendon comp......Acute Achilles tendon rupture alters the biomechanical properties of the plantar flexor muscle-tendon complex that can affect functional performance and the risk of repeat injury. The purpose of the present study was to compare the biomechanical properties of the plantar flexor muscle...... in the terminal part of dorsiflexion was found in the non-weightbearing group. The altered stiffness and strength in the affected limb could affect the coordination of gait and running....

  4. Basic Study and Clinical Implications of Left Ventricular False Tendon. Is it Associated With Innocent Murmur in Children or Heart Disease?

    Science.gov (United States)

    Sánchez Ferrer, Francisco; Sánchez Ferrer, María Luisa; Grima Murcia, María Dolores; Sánchez Ferrer, Marina; Sánchez del Campo, Francisco

    2015-08-01

    Left ventricular false tendon is a structure of unknown function in cardiac physiology that was first described anatomically by Turner. This condition may be related to various electrical or functional abnormalities, but no consensus has ever been reached. The purpose of this study was to determine the time of appearance, prevalence and histologic composition of false tendon, as well as its association with innocent murmur in children and with heart disease. The basic research was performed by anatomic dissection of hearts from adult human cadavers to describe false tendon and its histology. The clinical research consisted of echocardiographic study in a pediatric population to identify any relationship with heart disease, innocent murmur in children, or other abnormalities. Fetal echocardiography was performed prenatally at different gestational ages. False tendon was a normal finding in cardiac dissection and was composed of muscle and connective tissue fibers. In the pediatric population, false tendon was present in 83% on echocardiography and showed a statistically significant association only with innocent murmur in children and slower aortic acceleration. The presence of false tendon was first observed on fetal echocardiography from week 20 of pregnancy. Left ventricular false tendon is a normal finding visualized by fetal echocardiography from week 20 and is present until adulthood with no pathologic effects except for innocent murmur during childhood. It remains to be determined if false tendon is the cause of the murmurs or if its absence or structural anomalies are related to disease. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  5. MRI and gross anatomy of the iliopsoas tendon complex

    International Nuclear Information System (INIS)

    Polster, Joshua M.; Lee, Ho; Klika, Alison; Barsoum, Wael; Drake, Richard; Elgabaly, Mohamed

    2008-01-01

    The objective was to explain the anatomic basis of a longitudinal cleft of increased signal in the iliopsoas tendon seen on hip MR arthrograms. A prospective review of 20 MR hip arthrograms was performed using standard and fat-suppressed T1-weighted images to establish whether or not the cleft was composed of fatty tissue and to define the anatomy of the iliopsoas tendon complex. Three cadaver dissections of the hip region were then performed for anatomic correlation. Fourteen out of 20 MR hip arthrograms demonstrated a longitudinal cleft of increased T1 signal adjacent to the iliopsoas tendon, which suppressed on frequency selective fat-suppressed images, indicating fatty composition. Gross anatomic correlation demonstrated this fatty cleft to represent a fascial plane adjacent to the iliopsoas tendon, in one case separating the iliopsoas tendon medially from a thin intramuscular tendon within the lateral portion of the iliacus muscle. Also noted was a direct muscular insertion of the lateral portion of the iliacus muscle onto the anterior portion of the proximal femoral diaphysis in all 3 cadavers. The anatomy of the iliopsoas tendon complex is more complicated than typically illustrated and includes the iliopsoas tendon itself attaching to the lesser trochanter, the lateral portion of the iliacus muscle attaching directly upon the anterior portion of the proximal femoral diaphysis, and a thin intramuscular tendon within this lateral iliacus muscle that is separated from the iliopsoas tendon by a cleft of fatty fascia that accounts for the MRI findings of a cleft of increased T1 signal. (orig.)

  6. Quadriceps Tendon Rupture and Contralateral Patella Tendon Avulsion Post Primary Bilateral Total Knee Arthroplasty: A Case Report

    Directory of Open Access Journals (Sweden)

    Gaurav Sharma

    2016-07-01

    Full Text Available Background: Extensor mechanism failure secondary to knee replacement could be due to tibial tubercle avulsion, Patellar tendon rupture, patellar fracture or quadriceps tendon rupture. An incidence of Patella tendon rupture of 0.17% and Quadriceps tendon rupture of around 0.1% has been reported after Total knee arthroplasty. These are considered a devastating complication that substantially affects the clinical results and are challenging situations to treat with surgery being the mainstay of the treatment. Case Description: We report here an interesting case of a patellar tendon rupture of one knee and Quadriceps tendon rupture of the contralateral knee following simultaneous bilateral knee replacement in a case of inflammatory arthritis patient. End to end repair for Quadriceps tear and augmentation with Autologous Hamstring tendon graft was done for Patella tendon rupture. OUTCOME: Patient was followed up for a period of 1 year and there was no Extension lag with a flexion of 100 degrees in both the knees. DISCUSSION: The key learning points and important aspects of diagnosing these injuries early and the management techniques are described in this unique case of bilateral extensor mechanism disruption following knee replacements.

  7. Flexor tendon lacerations in zone V.

    Science.gov (United States)

    Stefanich, R J; Putnam, M D; Peimer, C A; Sherwin, F S

    1992-03-01

    Twenty-three patients with zone V flexor tendon lacerations rehabilitated by the Kleinert protocol were studied at an average of 46 months after trauma. Hand function was subjectively normal in only eight. Of fourteen patients who were employed at the time of injury, eight returned to their original occupations. Eight others were working at other jobs, and we considered six more capable of employment. Only one had a poor functional result that precluded occupational use of the hand. Pinch/grip strengths recovered to 85%/79% of the uninvolved side. Independent flexor digitorum superficialis/flexor digitorum profundus action was present in only seven patients. Sixteen regained full digital flexion. Extension loss averaged 25% at the wrist and 10% in each digit. As assessed by static two-point discrimination, sensibility was poor after associated median and ulnar nerve transections; this did not preclude good objective functional results. Complications included two tendon ruptures, proximal interphalangeal hyperextension in the presence of an unrepaired flexor digitorum superficialis, and limited motion in two patients after poor compliance in therapy. Tenolysis was needed in 4 of the 23. We now use a modified Duran technique for noncompliant patients and in those who are unable to extend their PIP joints because of weak intrinsic muscles.

  8. The Effect of Sodium Hyaluronate on Ligamentation and Biomechanical Property of Tendon in Repair of Achilles Tendon Defect with Polyethylene Terephthalate Artificial Ligament: A Rabbit Tendon Repair Model

    Directory of Open Access Journals (Sweden)

    Shengkun Li

    2016-01-01

    Full Text Available The Achilles tendon is the most common ruptured tendon of human body. Reconstruction with polyethylene terephthalate (PET artificial ligament is recommended in some serious cases. Sodium hyaluronate (HA is beneficial for the healing of tendon injuries. We aimed to determine the effect of sodium hyaluronate in repair of Achilles tendon defect with PET artificial ligament in an animal tendon repair model. Sixteen New Zealand White rabbits were divided into two groups. Eight rabbits repaired with PET were assigned to PET group; the other eight rabbits repaired with PET along with injection of HE were assigned to HA-PET group. All rabbits were sacrificed at 4 and 8 weeks postoperatively for biomechanical and histological examination. The HA-PET group revealed higher biomechanical property compared with the PET group. Histologically, more collagen tissues grew into the HA-PET group compared with PET group. In conclusion, application of sodium hyaluronate can improve the healing of Achilles tendon reconstruction with polyethylene terephthalate artificial ligament.

  9. Fetal development of the pulley for muscle insertion tendons: A review and new findings related to the tensor tympani tendon.

    Science.gov (United States)

    Rodríguez-Vázquez, Jose Francisco; Honkura, Yohei; Katori, Yukio; Murakami, Gen; Abe, Hiroshi

    2017-01-01

    The existence of hard tissue pulleys that act to change the direction of a muscle insertion tendon is well known in the human body. These include (1) the trochlea for the extraocular obliquus superior muscle, (2) the pterygoid hamulus for the tensor veli palatini muscle, (3) the deep sulcus on the plantar aspect of the cuboid bone for the peroneus longus tendon, (4) the lesser sciatic notch for the obturator internus muscle, and (5) the bony trochleariformis process for the tensor tympani muscle tendon. In addition, (6) the stapedius muscle tendon shows a lesser or greater angulation at the pyramidal eminence of the temporal bone. Our recent studies have shown that the development of pulleys Nos. 1 and 2 can be explained by a change in the topographical relationship between the pulley and the tendon, that of pulley No. 3 by the rapidly growing calcaneus pushing the tendon, and that of pulley No. 4 by migration of the insertion along the sciatic nerve and gluteus medius tendon. Therefore, in Nos. 1-4, an initially direct tendon curves secondarily and obtains an attachment to the pulley. In case No. 6, the terminal part of the stapedius tendon originates secondarily from the interzone mesenchymal tissue of the incudostapedial joint. In the case of pulley No. 5, we newly demonstrated that its initial phase of development was similar to No. 6, but the tensor tympani tendon achieved a right-angled turn under guidance by a specific fibrous tissue and it migrated along the growing malleus manubrium. Copyright © 2016 Elsevier GmbH. All rights reserved.

  10. Architecture and functional ecology of the human gastrocnemius muscle-tendon unit.

    Science.gov (United States)

    Butler, Erin E; Dominy, Nathaniel J

    2016-04-01

    The gastrocnemius muscle-tendon unit (MTU) is central to human locomotion. Structural variation in the human gastrocnemius MTU is predicted to affect the efficiency of locomotion, a concept most often explored in the context of performance activities. For example, stiffness of the Achilles tendon varies among individuals with different histories of competitive running. Such a finding highlights the functional variation of individuals and raises the possibility of similar variation between populations, perhaps in response to specific ecological or environmental demands. Researchers often assume minimal variation in human populations, or that industrialized populations represent the human species as well as any other. Yet rainforest hunter-gatherers, which often express the human pygmy phenotype, contradict such assumptions. Indeed, the human pygmy phenotype is a potential model system for exploring the range of ecomorphological variation in the architecture of human hindlimb muscles, a concept we review here. © 2015 Anatomical Society.

  11. Ablating hedgehog signaling in tenocytes during development impairs biomechanics and matrix organization of the adult murine patellar tendon enthesis.

    Science.gov (United States)

    Breidenbach, Andrew P; Aschbacher-Smith, Lindsey; Lu, Yinhui; Dyment, Nathaniel A; Liu, Chia-Feng; Liu, Han; Wylie, Chris; Rao, Marepalli; Shearn, Jason T; Rowe, David W; Kadler, Karl E; Jiang, Rulang; Butler, David L

    2015-08-01

    Restoring the native structure of the tendon enthesis, where collagen fibers of the midsubstance are integrated within a fibrocartilaginous structure, is problematic following injury. As current surgical methods fail to restore this region adequately, engineers, biologists, and clinicians are working to understand how this structure forms as a prerequisite to improving repair outcomes. We recently reported on the role of Indian hedgehog (Ihh), a novel enthesis marker, in regulating early postnatal enthesis formation. Here, we investigate how inactivating the Hh pathway in tendon cells affects adult (12-week) murine patellar tendon (PT) enthesis mechanics, fibrocartilage morphology, and collagen fiber organization. We show that ablating Hh signaling resulted in greater than 100% increased failure insertion strain (0.10 v. 0.05 mm/mm, p<0.01) as well as sub-failure biomechanical deficiencies. Although collagen fiber orientation appears overtly normal in the midsubstance, ablating Hh signaling reduces mineralized fibrocartilage by 32%, leading to less collagen embedded within mineralized tissue. Ablating Hh signaling also caused collagen fibers to coalesce at the insertion, which may explain in part the increased strains. These results indicate that Ihh signaling plays a critical role in the mineralization process of fibrocartilaginous entheses and may be a novel therapeutic to promote tendon-to-bone healing. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  12. Evaluation of the histological and mechanical features of tendon healing in a rabbit model with the use of second-harmonic-generation imaging and tensile testing.

    Science.gov (United States)

    Hase, E; Sato, K; Yonekura, D; Minamikawa, T; Takahashi, M; Yasui, T

    2016-11-01

    This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing. A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation. While the SHG light intensity of the healing tendon samples was significantly lower than that of the uninjured tendon samples, 2D Fourier transform SHG images showed a clear difference in collagen fibre structure between the uninjured and the healing samples, and among the healing samples. The mean intensity of the SHG image showed a moderate correlation (R 2 = 0.37) with Young's modulus obtained from the tensile testing. Our results indicate that SHG microscopy may be a potential indicator of tendon healing.Cite this article: E. Hase, K. Sato, D. Yonekura, T. Minamikawa, M. Takahashi, T. Yasui. Evaluation of the histological and mechanical features of tendon healing in a rabbit model with the use of second-harmonic-generation imaging and tensile testing. Bone Joint Res 2016;5:577-585. DOI: 10.1302/2046-3758.511.BJR-2016-0162.R1. © 2016 Yasui et al.

  13. Bevacizumab Improves Achilles Tendon Repair in a Rat Model

    Directory of Open Access Journals (Sweden)

    Herbert Tempfer

    2018-04-01

    Full Text Available Background/Aims: Effective wound-healing generally requires efficient re-vascularization after injury, ensuring sufficient supply with oxygen, nutrients, and various cell populations. While this applies to most tissues, tendons are mostly avascular in nature and harbor relatively few cells, probably contributing to their poor regenerative capacity. Considering the minimal vascularization of healthy tendons, we hypothesize that controlling angiogenesis in early tendon healing is beneficial for repair tissue quality and function. Methods: To address this hypothesis, Bevacizumab, a monoclonal antibody blocking VEGF-A signaling, was locally injected into the defect area of a complete tenotomy in rat Achilles tendon. At 28 days post-surgery, the defect region was investigated using immunohistochemistry against vascular and lymphatic epitopes. Polarization microscopy and biomechanical testing was used to determine tendon integrity and gait analysis for functional testing in treated vs non-treated animals. Results: Angiogenesis was found to be significantly reduced in the Bevacizumab treated repair tissue, accompanied by significantly reduced cross sectional area, improved matrix organization, increased stiffness and Young’s modulus, maximum load and stress. Further, we observed an improved gait pattern when compared to the vehicle injected control group. Conclusion: Based on the results of this study we propose that reducing angiogenesis after tendon injury can improve tendon repair, potentially representing a novel treatment-option.

  14. Tendon shift in hallux valgus: observations at MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Eustace, S. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Williamson, D. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Wilson, M. [Department of Orthopedics, Brigham and Womens Hospital, Boston, Massachusetts (United States); O`Byrne, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Bussolari, L. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Thomas, M. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States); Stephens, M. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Stack, J. [Department of Radiology, Boston University Medical Center Hospital, 88 East Newton Street, Atrium - 2, Boston, MA 02118 (United States); Weissman, B. [Department of Radiology, Brigham and Womens Hospital, Boston, Massachusetts (United States)

    1996-08-01

    Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. Results. There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. Conclusion. Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity. (orig.). With 4 figs., 1 tab.

  15. Tendon shift in hallux valgus: observations at MR imaging

    International Nuclear Information System (INIS)

    Eustace, S.; Williamson, D.; Wilson, M.; O'Byrne, J.; Bussolari, L.; Thomas, M.; Stephens, M.; Stack, J.; Weissman, B.

    1996-01-01

    Objective. This study was undertaken to demonstrate a shift in tendon alignment at the first metatarsophalangeal joint in patients with hallux valgus by means of magnetic resonance imaging. Design. Ten normal feet and 20 feet with the hallux valgus deformity conforming to conventional clinical and radiographic criteria were prospectively studied using magnetic resonance imaging. Correlation was made between tendon position at the first metatarsophalangeal joint and the severity of the hallux valgus deformity. Results. There is a significant shift in tendon position at the first metatarsophalangeal joint of patients with hallux valgus. The insertion of the abductor hallucis tendon is markedly plantarward and the flexor and extensor tendons bowstring at the first metatarsophalangeal joint compared with patients without the deformity. The severity of the tendon shift correlates with the hallux valgus angle and clinical severity of the hallux valgus deformity in each case. Conclusion. Patients with hallux valgus have a significant tendon shift at the first metatarsophalangeal joint which appears to contribute to development of the deformity. (orig.). With 4 figs., 1 tab

  16. In-depth imaging and quantification of degenerative changes associated with Achilles ruptured tendons by polarization-sensitive optical coherence tomography

    International Nuclear Information System (INIS)

    Bagnaninchi, P O; Yang, Y; Maffulli, G; El Haj, A; Maffulli, N; Bonesi, M; Meglinski, I; Phelan, C

    2010-01-01

    The objective of this study was to develop a method based on polarization-sensitive optical coherent tomography (PSOCT) for the imaging and quantification of degenerative changes associated with Achilles tendon rupture. Ex vivo PSOCT examinations were performed in 24 patients. The study involved samples from 14 ruptured Achilles tendons, 4 tendinopathic Achilles tendons and 6 patellar tendons (collected during total knee replacement) as non-ruptured controls. The samples were imaged in both intensity and phase retardation modes within 24 h after surgery, and birefringence was quantified. The samples were fixed and processed for histology immediately after imaging. Slides were assessed twice in a blind manner to provide a semi-quantitative histological score of degeneration. In-depth micro structural imaging was demonstrated. Collagen disorganization and high cellularity were observable by PSOCT as the main markers associated with pathological features. Quantitative assessment of birefringence and penetration depth found significant differences between non-ruptured and ruptured tendons. Microstructure abnormalities were observed in the microstructure of two out of four tendinopathic samples. PSOCT has the potential to explore in situ and in-depth pathological change associated with Achilles tendon rupture, and could help to delineate abnormalities in tendinopathic samples in vivo.

  17. A new non-metallic anchorage system for post-tensioning applications using CFRP tendons

    Science.gov (United States)

    Taha, Mahmoud Reda

    The objective of the work described in this thesis is to design, develop and test a new non-metallic anchorage system for post-tensioning applications using CFRP tendons. The use of a non-metallic anchorage system should eliminate corrosion and deterioration concerns in the anchorage zone. The development of a reliable non-metallic anchorage would provide an important contribution to this field of knowledge. The idea of the new anchorage is to hold the tendon through mechanical gripping. The anchorage consists of a barrel with a conical housing and four wedges. The anchorage components are made of ultra high performance concrete (UHPC) specially developed for the anchorage. Sixteen concrete mixtures with different casting and curing regimes were examined to develop four UHPC mixtures with compressive strengths in excess of 200 MPa. The UHPC mixtures showed very dense microstructures with some unique characteristics. To enhance the fracture toughness of the newly developed UHPC, analytical and experimental analyses were performed. Using 3 mm chopped carbon fibres, a significant increase in the fracture toughness of UHPC was achieved. The non-metallic anchorage was developed with the UHPC with enhanced fracture toughness. The barrel required careful wrapping with CFRP sheets to provide the confinement required to utilize the strength and toughness of the UHPC. Thirty-three anchorages were tested under both static and dynamic loading conditions. The non-metallic anchorage showed excellent mechanical performance and fulfilled the different requirements of a post-tensioning anchorage system. The development of the new non-metallic anchorage will widen the inclusion of CFRP tendons in post-tensioned concrete/masonry structures. The new system will offer the opportunity to exploit CFRP tendons effectively creating an innovative generation of corrosion-free, smart structures.

  18. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    OpenAIRE

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these mus...

  19. Stimulation of tendon repair by platelet concentrate, CDMP-2 and mechanical loading in animal models

    OpenAIRE

    Virchenko, Olena

    2007-01-01

    Growth factor delivery may be useful to accelerate the rate of tendon healing. We studied Platelet Concentrate, which in effect can be regarded as a cocktail of growth factors relevant for tendon healing. In a rat Achilles tendon transection model, one postoperative injection of Platelet Concentrate resulted in increased strength even 3 weeks later. Mechanical stimulation improves the repair of ruptured tendons. We studied the effects of platelets upon Achilles tendon regenerates in rats 3, 5...

  20. Complete rupture of the long head of the biceps tendon and the distal biceps tendon

    Directory of Open Access Journals (Sweden)

    Pieter J. Oberholzer

    2014-12-01

    Full Text Available The most common injury to the biceps muscle is rupture of the long head of the biceps tendon. A tear can occur proximally, distally or at the musculotendinous junction. Two cases are discussed, in both of which the patients felt a sudden sharp pain in the upper arm, at the shoulder and elbow respectively, and presented with a biceps muscle bump (Popeye deformity.

  1. Tendon collagen synthesis declines with immobilization in elderly humans

    DEFF Research Database (Denmark)

    Dideriksen, Kasper; Boesen, Anders P; Reitelseder, Søren

    2017-01-01

    -80 yr) were randomly assigned to NSAIDs (ibuprofen 1,200 mg/day; Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 wk and retrained for 6 wk. Tendon collagen protein synthesis, mechanical properties, size, expression of genes related to collagen turnover and remodeling, and signal...... intensity (from magnetic resonance imaging) were investigated. Tendon collagen synthesis decreased (P ... immobilization in both groups, whereas scleraxis mRNA decreased with inactivity in the Plc group only (P collagen protein synthesis decreased after 2 wk of immobilization, whereas tendon stiffness and modulus were only marginally reduced, and NSAIDs had no influence upon this...

  2. Ultrasound-based testing of tendon mechanical properties

    DEFF Research Database (Denmark)

    Seynnes, O R; Bojsen-Møller, J.; Albracht, K

    2015-01-01

    In the past 20 years, the use of ultrasound-based methods has become a standard approach to measure tendon mechanical properties in vivo. Yet the multitude of methodological approaches adopted by various research groups probably contribute to the large variability of reported values. The technique......, or signal synchronization; and 2) in physiological considerations related to the viscoelastic behavior or length measurements of tendons. Hence, the purpose of the present review is to assess and discuss the physiological and technical aspects connected to in vivo testing of tendon mechanical properties...

  3. Bone marrow-derived mesenchymal stem cells influence early tendon-healing in a rabbit achilles tendon model.

    Science.gov (United States)

    Chong, Alphonsus K S; Ang, Abel D; Goh, James C H; Hui, James H P; Lim, Aymeric Y T; Lee, Eng Hin; Lim, Beng Hai

    2007-01-01

    A repaired tendon needs to be protected for weeks until it has accrued enough strength to handle physiological loads. Tissue-engineering techniques have shown promise in the treatment of tendon and ligament defects. The present study tested the hypothesis that bone marrow-derived mesenchymal stem cells can accelerate tendon-healing after primary repair of a tendon injury in a rabbit model. Fifty-seven New Zealand White rabbits were used as the experimental animals, and seven others were used as the source of bone marrow-derived mesenchymal stem cells. The injury model was a sharp complete transection through the midsubstance of the Achilles tendon. The transected tendon was immediately repaired with use of a modified Kessler suture and a running epitendinous suture. Both limbs were used, and each side was randomized to receive either bone marrow-derived mesenchymal stem cells in a fibrin carrier or fibrin carrier alone (control). Postoperatively, the rabbits were not immobilized. Specimens were harvested at one, three, six, and twelve weeks for analysis, which included evaluation of gross morphology (sixty-two specimens), cell tracing (twelve specimens), histological assessment (forty specimens), immunohistochemistry studies (thirty specimens), morphometric analysis (forty specimens), and mechanical testing (sixty-two specimens). There were no differences between the two groups with regard to the gross morphology of the tendons. The fibrin had degraded by three weeks. Cell tracing showed that labeled bone marrow-derived mesenchymal stem cells remained viable and present in the intratendinous region for at least six weeks, becoming more diffuse at later time-periods. At three weeks, collagen fibers appeared more organized and there were better morphometric nuclear parameters in the treatment group (p tendon repair can improve histological and biomechanical parameters in the early stages of tendon-healing.

  4. TGIF1 Gene Silencing in Tendon-Derived Stem Cells Improves the Tendon-to-Bone Insertion Site Regeneration

    Directory of Open Access Journals (Sweden)

    Liyang Chen

    2015-11-01

    Full Text Available Background/Aims: The slow healing process of tendon-to-bone junctions can be accelerated via implanted tendon-derived stem cells (TDSCs with silenced transforming growth interacting factor 1 (TGIF1 gene. Tendon-to-bone insertion site is the special form of connective tissues derivatives of common connective progenitors, where TGF-β plays bidirectional effects (chondrogenic or fibrogenic through different signaling pathways at different stages. A recent study revealed that TGF-β directly induces the chondrogenic gene Sox9. However, TGIF1 represses the expression of the cartilage master Sox9 gene and changes its expression rate against the fibrogenesis gene Scleraxis (Scx. Methods: TGIF1 siRNA was transduced or TGIF1 was over-expressed in tendon-derived stem cells. Following suprapinatus tendon repair, rats were either treated with transduced TDSCs or nontransduced TDSCs. Histologic examination and Western blot were performed in both groups. Results: In this study, the silencing of TGIF1 significantly upregulated the chondrogenic genes and markers. Similarly, TGIF1 inhibited TDSC differentiation into cartilage via interactions with TGF-β-activated Smad2 and suppressed the phosphorylation of Smad2. The area of fibrocartilage at the tendon-bone interface was significantly increased in the TGIF1 (- group compared with the control and TGIF1-overexpressing groups in the early stages of the animal model. The interface between the tendon and bone showed a increase of new bone and fibrocartilage in the TGIF1 (- group at 4 weeks. Fibrovascular scar tissue was observed in the TGIF1-overexpressing group and the fibrin glue only group. Low levels of fibrocartilage and fibrovascular scar tissue were found in the TDSCs group. Conclusion: Collectively, this study shows that the tendon-derived stem cell modified with TGIF1 gene silencing has promising effects on tendon-to-bone healing which can be further explored as a therapeutic tool in regenerative medicine.

  5. The interfascicular matrix enables fascicle sliding and recovery in tendon, and behaves more elastically in energy storing tendons.

    Science.gov (United States)

    Thorpe, Chavaunne T; Godinho, Marta S C; Riley, Graham P; Birch, Helen L; Clegg, Peter D; Screen, Hazel R C

    2015-12-01

    While the predominant function of all tendons is to transfer force from muscle to bone and position the limbs, some tendons additionally function as energy stores, reducing the cost of locomotion. Energy storing tendons experience extremely high strains and need to be able to recoil efficiently for maximum energy storage and return. In the equine forelimb, the energy storing superficial digital flexor tendon (SDFT) has much higher failure strains than the positional common digital extensor tendon (CDET). However, we have previously shown that this is not due to differences in the properties of the SDFT and CDET fascicles (the largest tendon subunits). Instead, there is a greater capacity for interfascicular sliding in the SDFT which facilitates the greater extensions in this particular tendon (Thorpe et al., 2012). In the current study, we exposed fascicles and interfascicular matrix (IFM) from the SDFT and CDET to cyclic loading followed by a test to failure. The results show that IFM mechanical behaviour is not a result of irreversible deformation, but the IFM is able to withstand cyclic loading, and is more elastic in the SDFT than in the CDET. We also assessed the effect of ageing on IFM properties, demonstrating that the IFM is less able to resist repetitive loading as it ages, becoming stiffer with increasing age in the SDFT. These results provide further indications that the IFM is important for efficient function in energy storing tendons, and age-related alterations to the IFM may compromise function and predispose older tendons to injury. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Powered AFO for Achilles tendon rupture.

    Science.gov (United States)

    Yoshizawa, Nobuyuki

    2008-01-01

    This paper proposes a powered ankle foot orthosis (AFO) for the treatment of a ruptured Achilles tendon. Usually, conservative orthosis treatment requires about two months, and a motionless ankle degrades activities of daily living (ADL). It is difficult to go to school or work on foot, and a pair of crutches is needed to go up and down stairs. In order to improve the ADL, an electric powered AFO has been designed to improve the ability to walk with a fixed ankle joint. The sole of the proposed AFO is equipped with an electric actuator. The prototype actuator consists of Nd magnets and electromagnets and is lightweight and battery driven. The actuator can switch the upright posture and the stepped forward posture of the patient. In an experiment, the use of this electric AFO made it possible to walk and to ascend and descend stairs with a fixed ankle joint.

  7. Tension Stiffened and Tendon Actuated Manipulator

    Science.gov (United States)

    Doggett, William R. (Inventor); Dorsey, John T. (Inventor); Ganoe, George G. (Inventor); King, Bruce D. (Inventor); Jones, Thomas C. (Inventor); Mercer, Charles D. (Inventor); Corbin, Cole K. (Inventor)

    2015-01-01

    A tension stiffened and tendon actuated manipulator is provided performing robotic-like movements when acquiring a payload. The manipulator design can be adapted for use in-space, lunar or other planetary installations as it is readily configurable for acquiring and precisely manipulating a payload in both a zero-g environment and in an environment with a gravity field. The manipulator includes a plurality of link arms, a hinge connecting adjacent link arms together to allow the adjacent link arms to rotate relative to each other and a cable actuation and tensioning system provided between adjacent link arms. The cable actuation and tensioning system includes a spreader arm and a plurality of driven and non-driven elements attached to the link arms and the spreader arm. At least one cable is routed around the driven and non-driven elements for actuating the hinge.

  8. The 'bridging sign', a MR finding for combined full-thickness tears of the subscapularis tendon and the supraspinatus tendon

    International Nuclear Information System (INIS)

    Jung, Jin Young; Yoon, Young Cheol; Cha, Dong Ik; Yoo, Jae-Chul; Jung, Jee Young

    2013-01-01

    Background: In daily practice, we discovered one of the secondary magnetic resonance (MR) findings of the subscapularis (SSC) tendon tear, the 'bridging sign', which has not been previously described. Purpose: To describe the 'bridging sign' on shoulder MR imaging and its radiological and clinical significance in patients with SSC tendon tear. Material and Methods: Twenty-nine patients who had undergone shoulder arthroscopy and had full-thickness tear of the subscapularis tendon were enrolled. The medical records of the 29 patients were retrospectively reviewed for the duration of shoulder pain, rotator cuff tears, and associated arthroscopic findings: biceps tendon abnormality and superior glenoid labral tear. Then, preoperative shoulder MR images were retrospectively reviewed for the presence or absence of the 'bridging sign' and associated MR findings: periarticular fluid and fatty atrophy of the supraspinatus and subscapularis muscles. The type of rotator cuff tear associated with the 'bridging sign' was assessed and the sensitivity, specificity, and accuracy of the 'bridging sign' for the diagnosis of a certain type of rotator cuff tear were calculated. Associated arthroscopic and MR findings and mean duration of the shoulder pain between the patients with and without the 'bridging sign' were compared. Results: The 'bridging sign' was seen in 17 of 29 patients and corresponded to a complex of the torn and superomedially retracted subscapularis tendon, coracohumeral ligament, and superior glenohumeral ligament, adhered to the anterior margin of the torn supraspinatus (SSP) tendon on arthroscopy. All patients with the 'bridging sign' had combined full-thickness tear (FTT) of the cranial 1/2 portion of the subscapularis tendon and anterior 1/2 portion of the SSP tendon. The sensitivity, specificity, and accuracy of the 'bridging sign' for the diagnosis of combined FTTs of the SSC tendon and anterior portion of the SSP tendon were 81.0%, 100%, and 86

  9. Experimental and Computational Investigation of Viscoelasticity of Native and Engineered Ligament and Tendon

    Science.gov (United States)

    Ma, J.; Narayanan, H.; Garikipati, K.; Grosh, K.; Arruda, E. M.

    The important mechanisms by which soft collagenous tissues such as ligament and tendon respond to mechanical deformation include non-linear elasticity, viscoelasticity and poroelasticity. These contributions to the mechanical response are modulated by the content and morphology of structural proteins such as type I collagen and elastin, other molecules such as glycosaminoglycans, and fluid. Our ligament and tendon constructs, engineered from either primary cells or bone marrow stromal cells and their autogenous matricies, exhibit histological and mechanical characteristics of native tissues of different levels of maturity. In order to establish whether the constructs have optimal mechanical function for implantation and utility for regenerative medicine, constitutive relationships for the constructs and native tissues at different developmental levels must be established. A micromechanical model incorporating viscoelastic collagen and non-linear elastic elastin is used to describe the non-linear viscoelastic response of our homogeneous engineered constructs in vitro. This model is incorporated within a finite element framework to examine the heterogeneity of the mechanical responses of native ligament and tendon.

  10. Controlled Bioactive Molecules Delivery Strategies for Tendon and Ligament Tissue Engineering using Polymeric Nanofibers.

    Science.gov (United States)

    Hiong Teh, Thomas Kok; Hong Goh, James Cho; Toh, Siew Lok

    2015-01-01

    The interest in polymeric nanofibers has escalated over the past decade given its promise as tissue engineering scaffolds that can mimic the nanoscale structure of the native extracellular matrix. With functionalization of the polymeric nanofibers using bioactive molecules, localized signaling moieties can be established for the attached cells, to stimulate desired biological effects and direct cellular or tissue response. The inherently high surface area per unit mass of polymeric nanofibers can enhance cell adhesion, bioactive molecules loading and release efficiencies, and mass transfer properties. In this review article, the application of polymeric nanofibers for controlled bioactive molecules delivery will be discussed, with a focus on tendon and ligament tissue engineering. Various polymeric materials of different mechanical and degradation properties will be presented along with the nanofiber fabrication techniques explored. The bioactive molecules of interest for tendon and ligament tissue engineering, including growth factors and small molecules, will also be reviewed and compared in terms of their nanofiber incorporation strategies and release profiles. This article will also highlight and compare various innovative strategies to control the release of bioactive molecules spatiotemporally and explore an emerging tissue engineering strategy involving controlled multiple bioactive molecules sequential release. Finally, the review article concludes with challenges and future trends in the innovation and development of bioactive molecules delivery using polymeric nanofibers for tendon and ligament tissue engineering.

  11. Braided and Stacked Electrospun Nanofibrous Scaffolds for Tendon and Ligament Tissue Engineering.

    Science.gov (United States)

    Rothrauff, Benjamin B; Lauro, Brian B; Yang, Guang; Debski, Richard E; Musahl, Volker; Tuan, Rocky S

    2017-05-01

    Tendon and ligament injuries are a persistent orthopedic challenge given their poor innate healing capacity. Nonwoven electrospun nanofibrous scaffolds composed of polyesters have been used to mimic the mechanics and topographical cues of native tendons and ligaments. However, nonwoven nanofibers have several limitations that prevent broader clinical application, including poor cell infiltration, as well as tensile and suture-retention strengths that are inferior to native tissues. In this study, multilayered scaffolds of aligned electrospun nanofibers of two designs-stacked or braided-were fabricated. Mechanical properties, including structural and mechanical properties and suture-retention strength, were determined using acellular scaffolds. Human bone marrow-derived mesenchymal stem cells (MSCs) were seeded on scaffolds for up to 28 days, and assays for tenogenic differentiation, histology, and biochemical composition were performed. Braided scaffolds exhibited improved tensile and suture-retention strengths, but reduced moduli. Both scaffold designs supported expression of tenogenic markers, although the effect was greater on braided scaffolds. Conversely, cell infiltration was superior in stacked constructs, resulting in enhanced cell number, total collagen content, and total sulfated glycosaminoglycan content. However, when normalized against cell number, both designs modulated extracellular matrix protein deposition to a similar degree. Taken together, this study demonstrates that multilayered scaffolds of aligned electrospun nanofibers supported tenogenic differentiation of seeded MSCs, but the macroarchitecture is an important consideration for applications of tendon and ligament tissue engineering.

  12. Proteomic differences between native and tissue‐engineered tendon and ligament

    Science.gov (United States)

    Tew, Simon R.; Peffers, Mandy; Canty‐Laird, Elizabeth G.; Comerford, Eithne

    2016-01-01

    Tendons and ligaments (T/Ls) play key roles in the musculoskeletal system, but they are susceptible to traumatic or age‐related rupture, leading to severe morbidity as well as increased susceptibility to degenerative joint diseases such as osteoarthritis. Tissue engineering represents an attractive therapeutic approach to treating T/L injury but it is hampered by our poor understanding of the defining characteristics of the two tissues. The present study aimed to determine differences in the proteomic profile between native T/Ls and tissue engineered (TE) T/L constructs. The canine long digital extensor tendon and anterior cruciate ligament were analyzed along with 3D TE fibrin‐based constructs created from their cells. Native tendon and ligament differed in their content of key structural proteins, with the ligament being more abundant in fibrocartilaginous proteins. 3D T/L TE constructs contained less extracellular matrix (ECM) proteins and had a greater proportion of cellular‐associated proteins than native tissue, corresponding to their low collagen and high DNA content. Constructs were able to recapitulate native T/L tissue characteristics particularly with regard to ECM proteins. However, 3D T/L TE constructs had similar ECM and cellular protein compositions indicating that cell source may not be an important factor for T/L tissue engineering. PMID:27080496

  13. [Bursitis with severe tendon and muscle necrosis on the lateral stifle area in cattle].

    Science.gov (United States)

    Nuss, K; Räber, M; Sydler, T; Muggli, E; Hässig, M; Guscetti, F

    2011-11-01

    In 21 animals, chronic swelling on the lateral aspect of the stifle also known as «perigonitis», «stable-syndrome» or «bursitis bicipitalis femoris» were evaluated. Ultrasonography showed increased fluid in the distal subtendinous bursa of the biceps femoris muscle and structural changes in the tendons, muscles, subcutis and fasciae. Soft tissue swelling and an irregular contour of the lateral tibial condyle were typical signs on radiographs. Macroscopic changes were found at the insertion of the biceps femoris muscle, the distal subtendinous bursa of the biceps femoris muscle, the lateral collateral ligament of the stifle, the origin of muscles on the lateral femoral condyle and the lateral tibial condyle. They mainly consisted of tendon and muscle tissue necrosis with granulation tissue. Histology revealed areas of coagulation necrosis in tendons and ligaments, in which occasionally Onchocerca spp. were seen. The severity of lesions correlated well with the clinical signs, which were associated with a poor prognosis in advanced cases.

  14. Neuromuscular and muscle-tendon system adaptations to isotonic and isokinetic eccentric exercise.

    Science.gov (United States)

    Guilhem, G; Cornu, C; Guével, A

    2010-06-01

    To present the properties of an eccentric contraction and compare neuromuscular and muscle-tendon system adaptations induced by isotonic and isokinetic eccentric trainings. An eccentric muscle contraction is characterized by the production of muscle force associated to a lengthening of the muscle-tendon system. This muscle solicitation can cause micro lesions followed by a regeneration process of the muscle-tendon system. Eccentric exercise is commonly used in functional rehabilitation for its positive effect on collagen synthesis but also for resistance training to increase muscle strength and muscle mass in athletes. Indeed, eccentric training stimulates muscle hypertrophy, increases the fascicle pennation angle, fascicles length and neural activation, thus inducing greater strength gains than concentric or isometric training programs. Eccentric exercise is commonly performed either against a constant external load (isotonic) or at constant velocity (isokinetic), inducing different mechanical constraints. These different mechanical constraints could induce structural and neural adaptive strategies specific to each type of exercise. The literature tends to show that isotonic mode leads to a greater strength gain than isokinetic mode. This observation could be explained by a greater neuromuscular activation after IT training. However, the specific muscle adaptations induced by each mode remain difficult to determine due to the lack of standardized, comparative studies. 2010 Elsevier Masson SAS. All rights reserved.

  15. One-stage Pelnac Reconstruction in Full-thickness Skin Defects with Bone or Tendon Exposure

    Directory of Open Access Journals (Sweden)

    Xianghong Lou, MS

    2018-03-01

    Full Text Available Summary:. Dermal regeneration template, such as Integra and Pelnac, was originally designed for treating large area burn injury by inducing regeneration of dermis. To date, it has been widely applied in various acute and chronic wound sites. The present study demonstrated that application of artificial dermis alone induced 1-stage wound healing for wounds with bone or tendon exposure that should usually be repaired by flap surgery. Eight patients who presented with skin defects with bone and/or tendon exposure were treated by 1-stage Pelnac approach. All wounds healed within 20 weeks without skin graft or flap surgery. The wound area was reconstructed by nearly normal skin structure and linear scar. In the case of scalp defect, evidence of hair follicle cell migration and regeneration during healing process was observed. Thereby, the 1-stage Pelnac reconstitution can be considered as a novel method for inducing regrowth of epidermis and hair follicles to cure large full-thickness skin defect with bone and tendon exposure in 1 stage.

  16. Proteomic differences between native and tissue-engineered tendon and ligament.

    Science.gov (United States)

    Kharaz, Yalda A; Tew, Simon R; Peffers, Mandy; Canty-Laird, Elizabeth G; Comerford, Eithne

    2016-05-01

    Tendons and ligaments (T/Ls) play key roles in the musculoskeletal system, but they are susceptible to traumatic or age-related rupture, leading to severe morbidity as well as increased susceptibility to degenerative joint diseases such as osteoarthritis. Tissue engineering represents an attractive therapeutic approach to treating T/L injury but it is hampered by our poor understanding of the defining characteristics of the two tissues. The present study aimed to determine differences in the proteomic profile between native T/Ls and tissue engineered (TE) T/L constructs. The canine long digital extensor tendon and anterior cruciate ligament were analyzed along with 3D TE fibrin-based constructs created from their cells. Native tendon and ligament differed in their content of key structural proteins, with the ligament being more abundant in fibrocartilaginous proteins. 3D T/L TE constructs contained less extracellular matrix (ECM) proteins and had a greater proportion of cellular-associated proteins than native tissue, corresponding to their low collagen and high DNA content. Constructs were able to recapitulate native T/L tissue characteristics particularly with regard to ECM proteins. However, 3D T/L TE constructs had similar ECM and cellular protein compositions indicating that cell source may not be an important factor for T/L tissue engineering. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Preparation of collagen/polyurethane/knitted silk as a composite scaffold for tendon tissue engineering.

    Science.gov (United States)

    Sharifi-Aghdam, Maryam; Faridi-Majidi, Reza; Derakhshan, Mohammad Ali; Chegeni, Arash; Azami, Mahmoud

    2017-07-01

    The main objective of this study was to prepare a hybrid three-dimensional scaffold that mimics natural tendon tissues. It has been found that a knitted silk shows good mechanical strength; however, cell growth on the bare silk is not desirable. Hence, electrospun collagen/polyurethane combination was used to cover knitted silk. A series of collagen and polyurethane solutions (4%-7% w/v) in aqueous acetic acid were prepared and electrospun. According to obtained scanning electron microscopy images from pure collagen and polyurethane nanofibers, concentration was set constant at 5% (w/v) for blend solutions of collagen/polyurethane. Afterward, blend solutions with the weight ratios of 75/25, 50/50 and 25/75 were electrospun. Scanning electron microscopy images demonstrated the smooth and uniform morphology for the optimized nanofibers. The least fibers diameter among three weight ratios was found for collagen/polyurethane (25/75) which was 100.86 ± 40 nm and therefore was selected to be electrospun on the knitted silk. Attenuated total reflectance-Fourier transform infrared spectra confirmed the chemical composition of obtained electrospun nanofibers on the knitted silk. Tensile test of the specimens including blend nanofiber, knitted silk and commercial tendon substitute examined and indicated that collagen/polyurethane-coated knitted silk has appropriate mechanical properties as a scaffold for tendon tissue engineering. Then, Alamar Blue assay of the L929 fibroblast cell line seeded on the prepared scaffolds demonstrated appropriate viability of the cells with a significant proliferation on the scaffold containing more collagen content. The results illustrate that the designed structure would be promising for being used as a temporary substitute for tendon repair.

  18. MR imaging of subscapularis tendon injury in the setting of anterior shoulder dislocation

    Energy Technology Data Exchange (ETDEWEB)

    Gyftopoulos, Soterios; Carpenter, Elizabeth; Kazam, Jonathan; Babb, James; Bencardino, Jenny [NYU Hospital for Joint Diseases, New York, NY (United States)

    2012-11-15

    To evaluate the degree and location patterns of subscapularis tendon injury in patients with prior anterior shoulder dislocation (ASD). Forty-five consecutive MR shoulder examinations in patients with a history of ASD and 20 consecutive MR examinations in patients without prior dislocation were reviewed. Two readers assessed for the presence and location of tendinosis and tearing in the subscapularis tendon, which was divided into three segments: superior, middle, and inferior. The readers also documented the presence of anterior labral tears, osseous Bankart defects and Hill-Sachs lesions. Fisher's exact tests were performed to analyze the different types of pathology and their locations. Subscapularis tendinosis, and partial thickness and full thickness tears were more common in patients with a history of ASD. Tendinosis was found in 60-64.4% of the dislocation patients compared with 40% of the non-dislocation group. When stratified by location, the middle and inferior thirds were the most commonly affected with statistical significance (p < 0.05) found in tearing of the inferior third. Anterior labral tears, osseous Bankart defects, and Hill-Sachs lesions were more common in the dislocation group with statistically significant associations with tendinosis in the middle and inferior thirds and tearing of the middle third (p < 0.05). Our study suggests an association between middle and inferior subscapularis tendon pathology and prior anterior shoulder dislocation. Based on our results, careful MR assessment of the subscapularis tendon by the radiologist is indicated in the setting of ASD as injury of this structure can be symptomatic and may be amenable to treatment. (orig.)

  19. MR imaging of subscapularis tendon injury in the setting of anterior shoulder dislocation

    International Nuclear Information System (INIS)

    Gyftopoulos, Soterios; Carpenter, Elizabeth; Kazam, Jonathan; Babb, James; Bencardino, Jenny

    2012-01-01

    To evaluate the degree and location patterns of subscapularis tendon injury in patients with prior anterior shoulder dislocation (ASD). Forty-five consecutive MR shoulder examinations in patients with a history of ASD and 20 consecutive MR examinations in patients without prior dislocation were reviewed. Two readers assessed for the presence and location of tendinosis and tearing in the subscapularis tendon, which was divided into three segments: superior, middle, and inferior. The readers also documented the presence of anterior labral tears, osseous Bankart defects and Hill-Sachs lesions. Fisher's exact tests were performed to analyze the different types of pathology and their locations. Subscapularis tendinosis, and partial thickness and full thickness tears were more common in patients with a history of ASD. Tendinosis was found in 60-64.4% of the dislocation patients compared with 40% of the non-dislocation group. When stratified by location, the middle and inferior thirds were the most commonly affected with statistical significance (p < 0.05) found in tearing of the inferior third. Anterior labral tears, osseous Bankart defects, and Hill-Sachs lesions were more common in the dislocation group with statistically significant associations with tendinosis in the middle and inferior thirds and tearing of the middle third (p < 0.05). Our study suggests an association between middle and inferior subscapularis tendon pathology and prior anterior shoulder dislocation. Based on our results, careful MR assessment of the subscapularis tendon by the radiologist is indicated in the setting of ASD as injury of this structure can be symptomatic and may be amenable to treatment. (orig.)

  20. Three-dimensional study of pectoralis major muscle and tendon architecture.

    Science.gov (United States)

    Fung, Lillia; Wong, Brian; Ravichandiran, Kajeandra; Agur, Anne; Rindlisbacher, Tim; Elmaraghy, Amr

    2009-05-01

    A thorough understanding of the normal structural anatomy of the pectoralis major (PM) is of paramount importance in the planning of PM tendon transfers or repairs following traumatic PM tears. However, there is little consensus regarding the complex musculotendinous architecture of the PM in the anatomic or surgical literature. The purpose of this study is to model and quantify the three-dimensional architecture of the pectoralis muscle and tendon. Eleven formalin embalmed cadaveric specimens were examined: five (2M/3F) were serially dissected, digitized, and modeled in 3D using Autodesk Maya; six (4M/2F) were dissected and photographed. The PM tendon consisted of longer anterior and shorter posterior layers that were continuous inferiorly. The muscle belly consisted of an architecturally uniform clavicular head (CH) and a segmented sternal head (SH) with 6-7 segments. The most inferior SH segment in all specimens was found to fold anteriorly forming a trough that cradled the inferior aspect of the adjacent superior segment. No twisting of either the PM muscle or tendon was noted. Within the CH, the fiber bundle lengths (FBL) were found to increase from superior to inferior, whereas the mean FBLs of SH were greatest in segments 3-5 found centrally. The mean lateral pennation angle was greater in the CH (29.4 +/- 6.9 degrees ) than in the SH (20.6 +/- 2.7 degrees ). The application of these findings could form the basis of future studies to optimize surgical planning and functional recovery of repair/reconstruction procedures.

  1. Region specific patella tendon hypertrophy in humans following resistance training

    DEFF Research Database (Denmark)

    Kongsgaard, M.; Reitelseder, S; Pedersen, T.G.

    2007-01-01

    AIM: To examine if cross-sectional area (CSA) differs along the length of the human patellar tendon (PT), and if there is PT hypertrophy in response to resistance training. METHODS: Twelve healthy young men underwent baseline and post-training assessments. Maximal isometric knee extension strength...... (MVC) was determined unilaterally in both legs. PT CSA was measured at the proximal-, mid- and distal PT level and quadriceps muscle CSA was measured at mid-thigh level using magnetic resonance imaging. Mechanical properties of the patellar tendons were determined using ultrasonography. Subsequently....... CONCLUSIONS: To our knowledge, this study is the first to report tendon hypertrophy following resistance training. Further, the data show that the human PT CSA varies along the length of the tendon....

  2. Surgical treatment of partial biceps tendon ruptures at the elbow.

    Science.gov (United States)

    Dellaero, David T; Mallon, William J

    2006-01-01

    We present the treatment and results of a consecutive series of 7 patients (mean age, 42.7 years) with partial ruptures of the distal biceps tendon. All injuries occurred as the result of either heavy labor or weightlifting. Diagnosis in all cases was made with magnetic resonance imaging. After failure of conservative therapy, the patients were treated with repair of the distal biceps tendon. Mean follow-up was 30.6 months (range, 25-39 months). Results were uniformly good, with all patients satisfied with the outcome. All patients maintained their preoperative range of motion, with none reporting significant postoperative pain. The only complication was transient neurapraxias of the lateral antebrachial cutaneous nerve in 2 cases. We conclude that patients presenting with chronic pain in the cubital fossa should be evaluated for possible partial biceps tendon tear. If the diagnosis of partial tendon tear is made, surgical repair is a safe and effective method of treatment.

  3. Magnetic resonance imaging of Achilles tendon xanthomas in familial hypercholesterolemia

    International Nuclear Information System (INIS)

    Liem, M.S.L.; Bloem, J.L.; Schipper, J.

    1992-01-01

    The demonstration of tendon xanthomas is helpful in diagnosing heterozygous familial hypercholesterolemia. We investigated the possibility the lipid element with magnetic resonance (MR) imaging in seven patients with familial hypercholesterolemia and six controls. Although the mean relative signal intensities measured on long TR/TE spin echo sequences of the tendon were significantly higher in patients than in controls, the lack of such elevation does not rule out the presence of such lesions. MR imaging and US provide equal information on the anatomy of the Achilles tendon; as an abnormally increased signal intensity within the xanthoma on MRI was found in only a minority of our patients, the value of MRI in the demonstration of Achilles tendon xanthomas is limited when using conventional T1 and T2 spin echo sequences. (orig./DG)

  4. Bilateral giant cell tumor of tendon sheath of tendoachilles

    Directory of Open Access Journals (Sweden)

    Soma Datta

    2014-01-01

    Full Text Available Giant cell tumor of tendon sheath arises from the synovium of tendon sheaths, joints, or bursae, mostly affects adults between 30 and 50 years of age, and is slightly more common in females. We report the case of a 32-years-old male presenting with pain in both ankles without any history of trauma. On clinical examination, tenderness on both tendoachilles and local thickening were observed. Ultrasonography showed thickening of local tendinous area with increase in anteroposterior diameter, and Doppler demonstrated increased flow in peritendinous area. MRI findings showed that most of the tumor had intermediate signal intensity and portions of the tumor had low signal intensity. Fine needle aspiration cytology confirmed the diagnosis of giant cell tumor of tendon sheath. Excision biopsy was done with no recurrence on five month follow-up. Review of literature did not reveal any similar result; so, bilateral giant cell tumor of tendon sheath of tendoachilles is a rare presentation.

  5. Corticospinal excitability changes following prolonged muscle tendon vibration

    NARCIS (Netherlands)

    Steyvers, M.; Levin, O.; Baelen, M.G.M. van; Swinnen, S.P.

    2003-01-01

    The present experiment addressed the time course of corticospinal excitability changes following interventional muscle tendon vibration. Using transcranial magnetic stimulation, motor evoked potentials of the flexor carpi radialis and extensor carpi radialis brevis muscle were recorded for a period

  6. A rare knee extensor mechanism injury: Vastus intermedius tendon rupture

    Directory of Open Access Journals (Sweden)

    Engin Cetinkaya

    2015-01-01

    Conclusion: We report the first case of isolated rupture of the vastus intermedius tendon in the literature and we claim that disorder may be succesfully treated with conservative treatment and adequate physiotheraphy.

  7. [Achilles tendon xanthoma imaging on ultrasound and magnetic resonance imaging].

    Science.gov (United States)

    Fernandes, Eloy de Ávila; Santos, Eduardo Henrique Sena; Tucunduva, Tatiana Cardoso de Mello; Ferrari, Antonio J L; Fernandes, Artur da Rocha Correa

    2015-01-01

    The Achilles tendon xanthoma is a rare disease and has a high association with primary hyperlipidemia. An early diagnosis is essential to start treatment and change the disease course. Imaging exams can enhance diagnosis. This study reports the case of a 60-year-old man having painless nodules on his elbows and Achilles tendons without typical gout crisis, followed in the microcrystalline disease clinic of Unifesp for diagnostic workup. Laboratory tests obtained showed dyslipidemia. The ultrasound (US) showed a diffuse Achilles tendon thickening with hypoechoic areas. Magnetic resonance imaging (MRI) showed a diffuse tendon thickening with intermediate signal areas, and a reticulate pattern within. Imaging studies showed relevant aspects to diagnose a xanthoma, thus helping in the differential diagnosis. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

  8. Dextrose prolotherapy and corticosteroid injection into rat Achilles tendon.

    Science.gov (United States)

    Martins, C A Q; Bertuzzi, R T; Tisot, R A; Michelin, A F; do Prado, J M; Stroher, A; Burigo, M

    2012-10-01

    To assess the mechanical behavior and the histology of collagen fibers after prolotherapy with 12.5% dextrose into rat Achilles tendons and to compare with those of corticosteroid treatment. Out of 60 adult female Wistar rats (70 tendons), 15 received 12.5% dextrose (group I); 15 were treated with corticosteroid injection (group II); and 15 were given 0.9% saline injection (group III), all into the right Achilles tendon, whereas 13 animals received no injections (group IV). Three doses of each substance (groups I, II, and III) were given at a 5-day interval. Collagen fiber color was quantitatively assessed in three samples from each group and in five samples from the control group using picrosirius red staining under polarized and nonpolarized light. Twelve tendons from each group treated with the test substance and 20 tendons from the control group were submitted to the tensile strength test. There was no statistical difference across the groups with respect to maximum load at failure (n.s.) and absorbed energy (n.s.). With respect to tendon rupture, there was no difference between the myotendinous and the tendinous regions (n.s.). However, hematoxylin-eosin staining revealed statistical significance in lymphocytic inflammatory infiltrate (P = 0.008) and in parallel fiber orientation (P = 0.003) when comparing groups to the control group, without significance for either neovascularization (n.s.) or the presence of fibroblasts (n.s.). Likewise, there was no significant difference between the percentage of mature (n.s.) and immature (n.s.) fibers. Dextrose was not deleterious to the tendinous tissue, as it did not change the mechanical and histological properties of Achilles tendons in rats. The data obtained in this study may help clinicians in their daily work as they suggest that injections of 12.5% dextrose caused no harm to the tendons, although the clinical importance in humans still needs to be defined.

  9. Ultrasound Diagnosis of Bilateral Quadriceps Tendon Rupture After Statin Use

    Directory of Open Access Journals (Sweden)

    Nesselroade, Ryan D

    2010-09-01

    Full Text Available Simultaneous bilateral quadriceps tendon rupture is a rare injury. We report the case of bilateral quadriceps tendon rupture sustained with minimal force while refereeing a football game. The injury was suspected to be associated with statin use as the patient had no other identifiable risk factors.The diagnosis was confirmed using bedside ultrasound. [West J Emerg Med. 2010; 11(4:306-309.

  10. Sex Variation in Patellar Tendon Kinetics During Running

    Directory of Open Access Journals (Sweden)

    Sinclair Jonathan

    2015-06-01

    Full Text Available Purpose. The aim of the current investigation was to determine whether female recreational runners exhibit distinct patellar tendon loading patterns in relation to their male counterparts. Methods. Twelve male (age 26.55 ± 4.11 years, height 1.78 ± 0.11 m, mass 77.11 ± 5.06 kg and twelve female (age 26.67 ± 5.34 years, height 1.67 ± 0.12 m, mass 63.28 ± 9.75 kg runners ran over a force platform at 4.0 m · s-1. Lower limb kinematics were collected using an eight-camera optoelectric motion capture system which operated at 250 Hz. Patellar tendon loads were examined using a predictive algorithm. Sex differences in limb, knee and ankle joint stiffness were examined statistically using independent samples t tests. Results. The results indicate that patellar tendon force (male = 6.49 ± 2.28, female = 7.03 ± 1.35 and patelllar tendon loading rate (male = 92.41 ± 32.51, female = 111.05 ± 48.58 were significantly higher in female runners. Conclusions. Excessive tendon loading in female runners indicates that female runners may be at increased risk of patellar tendon pathologies.

  11. Association of gastrocnemius tendon calcification with chondrocalcinosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Foldes, K. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States)]|[University of California San Diego Medical Center (UCSD), San Diego, CA (United States)]|[National Institute of Rheumatology and Physiotherapy, Budapest (Hungary); Lenchik, L. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States)]|[University of California San Diego Medical Center (UCSD), San Diego, CA (United States); Jaovisidha, S. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States)]|[University of California San Diego Medical Center (UCSD), San Diego, CA (United States); Clopton, P. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States); Sartoris, D.J. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States)]|[University of California San Diego Medical Center (UCSD), San Diego, CA (United States); Resnick, D. [Department of Radiology, Veterans Administration Medical Center (VAMC), San Diego, CA (United States)]|[University of California San Diego Medical Center (UCSD), San Diego, CA (United States)

    1996-10-01

    Objective. Chondrocalcinosis of the knee is a common radiological finding in the elderly. However, visualization of chondrocalcinosis may be difficult in patients with advanced cartilage loss.The purpose of this study was to determine sensitivity, specificity, and accuracy of gastrocnemius tendon calcification that might serve as a radiographic marker of chondrocalcinosis in patients with painful knees. Design and patients. We prospectively evaluated 37 knee radiographs in 30 consecutive patients (29 men, 8 women; mean age 67 years, age range 37-90 years) with painful knees who had radiographic evidence of chondrocalcinosis. The frequency of fibrocartilage, hyaline cartilage, and gastrocnemius tendon calcification was determined. For a control group, we evaluated knee radiographs in 65 consecutive patients with knee pain (54 men, 11 women; mean age 59 years, age range 40-93 years) who had no radiological signs of chondrocalcinosis. The frequency of gastrocnemius tendon calcification in the control group was determined. Results. Gastrocnemius tendon calcification was 41% sensitive, 100% specific, and 78% accurate in predicting chondrocalcinosis. The gastrocnemius tendon was calcified on 15 of 37 (41%) radiographs in the experimental group and on 0 of 67 radiographs in the control group. In the chondrocalcinosis group, 23 (62%) had posterior hyaline cartilage calcification, 14 (38%) had anterior hyaline cartilage calcification, 31 (84%) had medial meniscus calcification, and 36 (97%) had lateral meniscus calcification. Conclusions. Our results show that gastrocnemius tendon calcification is an accurate radiographic marker of chondrocalcinosis in patients with knee pain. (orig.). With 2 figs., 2 tabs.

  12. Association of gastrocnemius tendon calcification with chondrocalcinosis of the knee

    International Nuclear Information System (INIS)

    Foldes, K.; Lenchik, L.; Jaovisidha, S.; Clopton, P.; Sartoris, D.J.; Resnick, D.

    1996-01-01

    Objective. Chondrocalcinosis of the knee is a common radiological finding in the elderly. However, visualization of chondrocalcinosis may be difficult in patients with advanced cartilage loss.The purpose of this study was to determine sensitivity, specificity, and accuracy of gastrocnemius tendon calcification that might serve as a radiographic marker of chondrocalcinosis in patients with painful knees. Design and patients. We prospectively evaluated 37 knee radiographs in 30 consecutive patients (29 men, 8 women; mean age 67 years, age range 37-90 years) with painful knees who had radiographic evidence of chondrocalcinosis. The frequency of fibrocartilage, hyaline cartilage, and gastrocnemius tendon calcification was determined. For a control group, we evaluated knee radiographs in 65 consecutive patients with knee pain (54 men, 11 women; mean age 59 years, age range 40-93 years) who had no radiological signs of chondrocalcinosis. The frequency of gastrocnemius tendon calcification in the control group was determined. Results. Gastrocnemius tendon calcification was 41% sensitive, 100% specific, and 78% accurate in predicting chondrocalcinosis. The gastrocnemius tendon was calcified on 15 of 37 (41%) radiographs in the experimental group and on 0 of 67 radiographs in the control group. In the chondrocalcinosis group, 23 (62%) had posterior hyaline cartilage calcification, 14 (38%) had anterior hyaline cartilage calcification, 31 (84%) had medial meniscus calcification, and 36 (97%) had lateral meniscus calcification. Conclusions. Our results show that gastrocnemius tendon calcification is an accurate radiographic marker of chondrocalcinosis in patients with knee pain. (orig.). With 2 figs., 2 tabs

  13. Suture anchor tenodesis in repair of distal Achilles tendon injuries.

    Science.gov (United States)

    Kiliçoğlu, Onder; Türker, Mehmet; Yildız, Fatih; Akalan, Ekin; Temelli, Yener

    2014-01-01

    Distal Achilles tendon avulsions are in the form of either bony and nonbony avulsion of Achilles tendon from its calcaneal insertion. Four patients with distal Achilles tendon avulsions or ruptures which were treated with tendon to bone repair using suture anchors are presented here. Operated leg was immobilized in above-knee cast for 4 weeks while the patient walked non-weight-bearing. Then, cast was changed to below knee, and full weight-bearing was allowed. Patients underwent gait analysis minimum at first postoperative year. Mean American Orthopedics Foot Ankle Society ankle/hindfoot score of patients at last visit was 88.75 (range 85-100), and Achilles tendon total rupture score was 77.75 (range 58-87). Mean passive dorsiflexion of injured ankles (14° ± 5°) was lower than uninjured ankles (23° ± 9°). All the kinematic parameters of gait analysis were comparable to the uninjured side. Maximum plantar flexion power of injured ankle was 1.40 W/kg, and this was significantly lower than the contralateral side value 2.38 W/kg; (P = 0.0143). There were no visually altered gait or problems in daily life. Suture anchor tenodesis technique of distal Achilles tendon avulsions was successful in achieving durable osteotendinous repairs.

  14. The anatomical footprint of the Achilles tendon: a cadaveric study.

    Science.gov (United States)

    Ballal, M S; Walker, C R; Molloy, A P

    2014-10-01

    We dissected 12 fresh-frozen leg specimens to identify the insertional footprint of each fascicle of the Achilles tendon on the calcaneum in relation to their corresponding muscles. A further ten embalmed specimens were examined to confirm an observation on the retrocalcaneal bursa. The superficial part of the insertion of the Achilles tendon is represented by fascicles from the medial head of the gastrocnemius muscle, which is inserted over the entire width of the inferior facet of the calcaneal tuberosity. In three specimens this insertion was in continuity with the plantar fascia in the form of periosteum. The deep part of the insertion of the Achilles tendon is made of fascicles from the soleus tendon, which insert on the medial aspect of the middle facet of the calcaneal tuberosity, while the fascicles of the lateral head of the gastrocnemius tendon insert on the lateral aspect of the middle facet of the calcaneal tuberosity. A bicameral retrocalcaneal bursa was present in 15 of the 22 examined specimens. This new observation and description of the insertional footprint of the Achilles tendon and the retrocalcaneal bursa may allow a better understanding of the function of each muscular part of the gastrosoleus complex. This may have clinical relevance in the treatment of Achilles tendinopathies. ©2014 The British Editorial Society of Bone & Joint Surgery.

  15. Modified rerouting procedure for failed peroneal tendon dislocation surgery.

    Science.gov (United States)

    Gaulke, R; Hildebrand, F; Panzica, M; Hüfner, T; Krettek, C

    2010-04-01

    Recurrent dislocation of the peroneal tendons following operative treatment is relatively uncommon, but can be difficult to treat. We asked whether subligamental transposition of the peroneus brevis tendon, fibular grooving, and reattachment of the superior peroneal retinaculum for failed peroneal tendon dislocation surgery would achieve a stable fixation of the peroneal tendons and whether there would be restrictions of ROM or instability of the hindfoot. We reviewed six female patients (mean age, 24.5 years) with general laxity of joints preoperatively and at 6 weeks and 3, 6, and 12 months postoperatively. Within 1 year postoperatively no recurrence was found. In two ankles the extension was restricted 5 degrees to 10 degrees . In another pronation and supination was restricted 5 degrees each. Stability of the ankle increased in four patients and stayed unchanged in two. AOFAS score increased from a mean value of 36 +/- 20.6 preoperatively to 90 +/- 7 postoperatively at 1 year. We conclude transposition of the peroneus brevis tendon is a reasonable treatment for failed peroneal tendon dislocation surgery. Level IV, therapeutic study (prospective case series). See Guidelines for Authors for a complete description of levels of evidence.

  16. Review of inservice inspections of greased tendons in prestressed-concrete containments

    International Nuclear Information System (INIS)

    Dougan, J.R.; Ashar, H.

    1983-01-01

    Prestressed-concrete containments in the United States using greased prestressing tendons are inspected periodically to ensure structural integrity and to identify and correct problem areas before they become critical. An analysis of the available utility inspection data and an evaluation of the current and proposed guidelines were conducted to provide a measure of the reliability of the inspection process. Comments from utility and industry personnel were factored into the analysis. The results indicated that the majority of the few incidences of problems or abnormalities which occurred were minor in nature and did not threaten the structural integrity of the containment

  17. Glutaraldehyde cross-linking of tendon mechanical effects at the level of the tendon fascicle and fibril

    DEFF Research Database (Denmark)

    Hansen, Philip; Hassenkam, Tue; Svensson, Rene Bruggebusch

    2009-01-01

    at the tendon fibril level were examined by atomic force microscopy. Peak forces increased from approximately 1379 to approximately 2622 pN while an extended Hertz fit of force-indentation data showed a approximately 24 fold increase in Young's modulus on indentation. The effect of glutaraldehyde cross......Conclusive insight into the microscopic principles that govern the strength of tendon and related connective tissues is lacking and the importance of collagen cross-linking has not been firmly established. The combined application of whole-tissue mechanical testing and atomic force spectroscopy...... allowed for a detailed characterization of the effect of cross-linking in rat-tail tendon. The cross-link inducing agent glutaraldehyde augmented the tensile strength of tendon fascicles. Stress at failure increased from approximately 8 MPa to approximately 39 MPa. The mechanical effects of glutaraldehyde...

  18. Glutaraldehyde Cross-Linking of TendonMechanical Effects at the Level of the Tendon Fascicle and Fibril

    DEFF Research Database (Denmark)

    Hansen, P.; Svensson, R.B.; Aagaard, P.

    2009-01-01

    were examined by atomic force microscopy. Peak forces increased from 1379 to 2622 pN while an extended Hertz fit of force-indentation data showed a 24 fold increase in Young's modulus on indentation. The effect of glutaraldehyde cross-linking on the tensile properties of a single collagen fibril......Conclusive insight into the microscopic principles that govern the strength of tendon and related connective tissues is lacking and the importance of collagen cross-linking has not been firmly established. The combined application of whole-tissue mechanical testing and atomic force spectroscopy...... allowed for a detailed characterization of the effect of cross-linking in rat-tail tendon. The cross-link inducing agent glutaraldehyde augmented the tensile strength of tendon fascicles. Stress at failure increased from 8 MPa to 39 MPa. The mechanical effects of glutaraldehyde at the tendon fibril level...

  19. [Reconstruction of chronic Achilles tendon rupture with flexor hallucis longus tendon harvested using a minimally invasive technique].

    Science.gov (United States)

    Miao, Xudong; Wu, Yongping; Tao, Huimin; Yang, Disheng

    2011-07-01

    To evaluate the effectiveness of flexor hallucis longus tendon harvested using a minimally invasive technique in reconstruction of chronic Achilles tendon rupture. Between July 2006 and December 2009, 22 patients (22 feet) with chronic Achilles tendon rupture were treated, including 16 males and 6 females with a median age of 48 years (range, 28-65 years). The disease duration was 27-1,025 days (median, 51 days). Twenty-one patients had hooflike movement's history and 1 patient had no obvious inducement. The result of Thompson test was positive in 22 cases. The score was 53.04 +/- 6.75 according to American Orthopedic Foot and Ankle Society (AOFAS) ankle and hindfoot score system. MRI indicated that the gap of the chronic Achilles tendon rupture was 4.2-8.0 cm. A 3 cm-long incision was made vertically in the plantar aspect of the midfoot and a 1 cm-long transverse incision was made in a plantar flexor crease at the base of the great toe to harvest flexor hallucis longus tendon. The flexor hallucis longus tendon was 10.5-13.5 cm longer from tuber calcanei to the end of the Achilles tendon, and then the tendon was fixed to the tuber calcanei using interface screws or anchor nail after they were woven to form reflexed 3-bundle and sutured. Wound healed by first intention in all patients and no early complication occurred. Twenty-two patients were followed up 12-42 months (mean, 16.7 months). At 12 months after operation, The AOFAS ankle and hindfoot score was 92.98 +/- 5.72, showing significant difference when compared with that before operation (t= -40.903, P=0.000). The results were excellent in 18 cases, good in 2 cases, and fair in 2 cases with an excellent and good rate of 90.9%. No sural nerve injury, posterior tibial nerve injury, plantar painful scar, medial plantar nerve injury, and lateral plantar nerve injury occurred. Chronic Achilles tendon rupture reconstruction with flexor hallucis longus tendon harvested using a minimally invasive technique offers a

  20. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium

    OpenAIRE

    Shishani, Yousef; Streit,Jonathan; Rodgers,Mark; Gobezie,Reuben

    2015-01-01

    Jonathan J Streit,1 Yousef Shishani,1 Mark Rodgers,2 Reuben Gobezie1 1The Cleveland Shoulder Institute, 2Department of Pathology, University Hospitals of Cleveland, Cleveland, OH, USA Background: Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB) tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon an...

  1. MRI T2 mapping of the asymptomatic supraspinatus tendon by age and imaging plane using clinically relevant subregions

    Energy Technology Data Exchange (ETDEWEB)

    Anz, Adam W., E-mail: anz.adam.w@gmail.com [The Steadman Clinic, Vail, CO (United States); Lucas, Erin P., E-mail: erin.lucas14@gmail.com [Steadman Philippon Research Institute, Vail, CO (United States); Fitzcharles, Eric K., E-mail: ericfitzcharles@gmail.com [Steadman Philippon Research Institute, Vail, CO (United States); Surowiec, Rachel K., E-mail: Rachel.surowiec@sprivail.org [Steadman Philippon Research Institute, Vail, CO (United States); Millett, Peter J., E-mail: drmillett@thesteadmanclinic.com [The Steadman Clinic, Vail, CO (United States); Ho, Charles P., E-mail: Charles.ho@sprivail.org [Steadman Philippon Research Institute, Vail, CO (United States)

    2014-05-15

    Purpose: Diagnosis of partial rotator cuff tears and tendonopathy using conventional MRI has proven variable. Quantitative T2 mapping may have application for assessing rotator cuff health. In order to evaluate the usefulness of T2 mapping for the rotator cuff, methods must be refined for mapping the supraspinatus tendon, and normative T2 values must first be acquired. Materials and methods: This study was IRB approved. Thirty asymptomatic volunteers (age: 18–62) were evaluated with sagittal and coronal T2 mapping sequences. Manual segmentation of tendon and muscle as a unit and tendon alone was performed twice by two independent raters. Segmentations were divided into medial, middle and lateral subregions and mean T2 values calculated. Results: Anatomic comparison of mean T2 values illustrated highest values in the medial region, lowest values in the lateral region, and intermediate values for the middle region upon coronal segmentation (p < 0.001). In sagittal segmentations, there were higher values in the medial region and no significant differences between the lateral and middle subregions. No significant differences were found with comparison across age groups. Inter and intra-rater segmentation repeatability was excellent, with coefficients ranging from 0.85 to 0.99. Conclusion: T2 mapping illustrated anatomic variation along the supraspinatus muscle-tendon unit with low standard deviations and excellent repeatability, suggesting that changes in structure due to degeneration or changes associated with healing after repair may be detectable.

  2. Effectiveness of the Simultaneous Stretching of the Achilles Tendon and Plantar Fascia in Individuals With Plantar Fasciitis.

    Science.gov (United States)

    Engkananuwat, Phoomchai; Kanlayanaphotporn, Rotsalai; Purepong, Nithima

    2018-01-01

    Since the plantar fascia and the Achilles tendon are anatomically connected, it is plausible that stretching of both structures simultaneously will result in a better outcome for plantar fasciitis. Fifty participants aged 40 to 60 years with a history of plantar fasciitis greater than 1 month were recruited. They were prospectively randomized into 2 groups. Group 1 was instructed to stretch the Achilles tendon while group 2 simultaneously stretched the Achilles tendon and plantar fascia. After 4 weeks of both stretching protocols, participants in group 2 demonstrated a significantly greater pressure pain threshold than participants in group 1 ( P = .040) with post hoc analysis. No significant differences between groups were demonstrated in other variables ( P > .05). Concerning within-group comparisons, both interventions resulted in significant reductions in pain at first step in the morning and average pain at the medial plantar calcaneal region over the past 24 hours, while there were increases in the pressure pain threshold, visual analog scale-foot and ankle score, and range of motion in ankle dorsiflexion ( P plantar fascia for 4 weeks was a more effective intervention for plantar fasciitis. Patients who reported complete relief from symptoms at the end of the 4-week intervention in the simultaneous stretching group (n = 14; 56%) were double that of the stretching of the Achilles tendon-only group (n = 7; 28%). II, lesser quality RCT or prospective comparative study.

  3. MRI T2 mapping of the asymptomatic supraspinatus tendon by age and imaging plane using clinically relevant subregions

    International Nuclear Information System (INIS)

    Anz, Adam W.; Lucas, Erin P.; Fitzcharles, Eric K.; Surowiec, Rachel K.; Millett, Peter J.; Ho, Charles P.

    2014-01-01

    Purpose: Diagnosis of partial rotator cuff tears and tendonopathy using conventional MRI has proven variable. Quantitative T2 mapping may have application for assessing rotator cuff health. In order to evaluate the usefulness of T2 mapping for the rotator cuff, methods must be refined for mapping the supraspinatus tendon, and normative T2 values must first be acquired. Materials and methods: This study was IRB approved. Thirty asymptomatic volunteers (age: 18–62) were evaluated with sagittal and coronal T2 mapping sequences. Manual segmentation of tendon and muscle as a unit and tendon alone was performed twice by two independent raters. Segmentations were divided into medial, middle and lateral subregions and mean T2 values calculated. Results: Anatomic comparison of mean T2 values illustrated highest values in the medial region, lowest values in the lateral region, and intermediate values for the middle region upon coronal segmentation (p < 0.001). In sagittal segmentations, there were higher values in the medial region and no significant differences between the lateral and middle subregions. No significant differences were found with comparison across age groups. Inter and intra-rater segmentation repeatability was excellent, with coefficients ranging from 0.85 to 0.99. Conclusion: T2 mapping illustrated anatomic variation along the supraspinatus muscle-tendon unit with low standard deviations and excellent repeatability, suggesting that changes in structure due to degeneration or changes associated with healing after repair may be detectable

  4. The influence of exercise during growth on ultrasonographic parameters of the superficial digital flexor tendon of young Thoroughbred horses.

    Science.gov (United States)

    Moffat, P A; Firth, E C; Rogers, C W; Smith, R K W; Barneveld, A; Goodship, A E; Kawcak, C E; McIlwraith, C W; van Weeren, P R

    2008-03-01

    Conditioning by early training may influence the composition of certain musculoskeletal tissues, but very few data exist on its effect during growth on tendon structure and function. To investigate whether conditioning exercise in young foals would lead to any ultrasonographically detectable damage to the superficial digital flexor tendon or an increase in cross-sectional area (CSA). Thirty-three Thoroughbred foals reared at pasture were allocated to 2 groups: control (PASTEX) allowed exercise freely at pasture; and CONDEX, also at pasture, began conditioning exercise from mean age 21 days over 1030 m on a purpose-built oval grass track, for 5 days/week until mean age 18 months. Foals were observed daily, and underwent orthopaedic examination monthly. Ultrasonographic images of the superficial digital flexor tendon (SDFT) at the mid-metacarpal level of both forelimbs were obtained in all foals at ages 5, 8, 12, 15 and 18 months. CSA was validated (r(2) = 0.89) by determining CSA from digital photographs of the transected SDFT surface from 12 of the horses necropsied at age 17.1 months. here was no clinical or ultrasonographic evidence of tendonopathy in either group and the greatest increase in mean CSA in both groups occurred between age 5 and 8 months. Across all age categories, there was no significant difference in mean CSA between the left and right limbs, or colts and fillies; there was a trend towards a larger CSA in the CONDEX group (P = 0.058). There was no conclusive evidence for a structural adaptive hypertrophy of the SDFT, probably because the regimen was insufficiently rigorous or because spontaneous pasture exercise may induce maximal development of energy storing tendons. A moderate amount of early conditioning exercise against a background of constant exercise at pasture is not harmful to the development of the flexor tendons.

  5. The blood-tendon barrier: identification and characterisation of a novel tissue barrier in tendon blood vessels

    Directory of Open Access Journals (Sweden)

    C Lehner

    2016-05-01

    Full Text Available Tissue barriers function as “gate keepers” between different compartments (usually blood and tissue and are formed by specialised membrane-associated proteins, localising to the apicolateral plasma membrane domain of epithelial and endothelial cells. By sealing the paracellular space, the free diffusion of solutes and molecules across epithelia and endothelia is impeded. Thereby, tissue barriers contribute to the establishment and maintenance of a distinct internal and external environment, which is crucial during organ development and allows maintenance of an organ-specific homeostatic milieu. So far, various epithelial and endothelial tissue barriers have been described, including the blood-brain barrier, the blood-retina barrier, the blood-testis barrier, the blood-placenta barrier, and the cerebrospinal fluid (CSF-brain barrier, which are vital for physiological function and any disturbance of these barriers can result in severe organ damage or even death. Here, we describe the identification of a novel barrier, located in the vascular bed of tendons, which we term the blood-tendon barrier (BTB. By using immunohistochemistry, transmission electron microscopy, and tracer studies we demonstrate the presence of a functional endothelial barrier within tendons restricting the passage of large blood-borne molecules into the surrounding tendon tissue. We further provide in vitro evidence that the BTB potentially contributes to the creation of a distinct internal tissue environment impacting upon the proliferation and differentiation of tendon-resident cells, effects which might be fundamental for the onset of tendon pathologies.

  6. Methods of Assessing Human Tendon Metabolism and Tissue Properties in Response to Changes in Mechanical Loading

    DEFF Research Database (Denmark)

    Heinemeier, Katja M; Kjaer, Michael; Magnusson, S Peter

    2016-01-01

    expression as well as protein synthesis rate. Further the (14)C bomb-pulse method has provided data on long-term tissue turnover in human tendon. Non-invasive techniques allow measurement of tendon metabolism (positron emission tomography (PET)), tendon morphology (magnetic resonance imaging (MRI......In recent years a number of methodological developments have improved the opportunities to study human tendon. Microdialysis enables sampling of interstitial fluid in the peritendon tissue, while sampling of human tendon biopsies allows direct analysis of tendon tissue for gene- and protein...

  7. A photoactivated nanofiber graft material for augmented Achilles tendon repair.

    Science.gov (United States)

    Ni, Tao; Senthil-Kumar, Prabhu; Dubbin, Karen; Aznar-Cervantes, Salvador D; Datta, Néha; Randolph, Mark A; Cenis, José L; Rutledge, Gregory C; Kochevar, Irene E; Redmond, Robert W

    2012-10-01

    Suture repair of Achilles tendon rupture can cause infection, inflammation and scarring, while prolonged immobilization promotes adhesions to surrounding tissues and joint stiffness. Early mobilization can reduce complications provided the repair is strong enough to resist re-rupture. We have developed a biocompatible, photoactivated tendon wrap from electrospun silk (ES) to provide additional strength to the repair that could permit early mobilization, and act as a barrier to adhesion formation. ES nanofiber mats were prepared by electrospinning. New Zealand white rabbits underwent surgical transection of the Achilles tendon and repair by: (a) SR: standard Kessler suture + epitendinous suture (5-0 vicryl). (b) ES/PTB: a single stay suture and a section of ES mat, stained with 0.1% Rose Bengal (RB), wrapped around the tendon and bonded with 532 nm light (0.3 W/cm(2) , 125 J/cm(2) ). (c) SR + ES/PTB: a combination of (a) and (b). Gross appearance, extent of adhesion formation and biomechanical properties of the repaired tendon were evaluated at Days 7, 14, or 28 post-operatively (n = 8 per group at each time point). Ultimate stress (US) and Young's modulus (E) in the SR group were not significantly different from the ES/PTB group at Days 7 (US, P = 0.85; E, P = 1), 14 (US, P = 0.054; E, P = 1), and 28 (US, P = 0.198; E, P = 0.12) post-operatively. Adhesions were considerably greater in the SR group compared to the ES/PTB group at Days 7 (P = 0.002), 14 (P tendon repair site provides considerable benefit in Achilles tendon repair. Lasers Surg. Med. 44: 645-652, 2012. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.

  8. Plantar fascia anatomy and its relationship with Achilles tendon and paratenon.

    Science.gov (United States)

    Stecco, Carla; Corradin, Marco; Macchi, Veronica; Morra, Aldo; Porzionato, Andrea; Biz, Carlo; De Caro, Raffaele

    2013-12-01

    Although the plantar fascia (PF) has been studied quite well from a biomechanical viewpoint, its microscopic properties have been overlooked: nothing is known about its content of elastic fibers, the features of the extracellular matrix or the extent of innervation. From a functional and clinical standpoint, the PF is often correlated with the triceps surae muscle, but the anatomical grounds for this link are not clear. The aim of this work was to focus on the PF macroscopic and microscopic properties and study how Achilles tendon diseases might affect it. Twelve feet from unembalmed human cadavers were dissected to isolate the PF. Specimens from each PF were tested with various histological and immunohistochemical stains. In a second stage, 52 magnetic resonance images (MRI) obtained from patients complaining of aspecific ankle or foot pain were analyzed, dividing the cases into two groups based on the presence or absence of signs of degeneration and/or inflammation of the Achilles tendon. The thickness of PF and paratenon was assessed in the two groups and statistical analyses were conducted. The PF is a tissue firmly joined to plantar muscles and skin. Analyzing its possible connections to the sural structures showed that this fascia is more closely connected to the paratenon of Achilles tendon than to the Achilles tendon, through the periosteum of the heel. The PF extended medially and laterally, continuing into the deep fasciae enveloping the abductor hallucis and abductor digiti minimi muscles, respectively. The PF was rich in hyaluronan, probably produced by fibroblastic-like cells described as 'fasciacytes'. Nerve endings and Pacini and Ruffini corpuscles were present, particularly in the medial and lateral portions, and on the surface of the muscles, suggesting a role for the PF in the proprioception of foot. In the radiological study, 27 of the 52 MRI showed signs of Achilles tendon inflammation and/or degeneration, and the PF was 3.43 ± 0.48 mm thick

  9. Effects of celecoxib on proliferation and tenocytic differentiation of tendon-derived stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Kairui; Zhang, Sheng [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Li, Qianqian [Cancer Research Institute, Southern Medical University, Guangzhou 510515 (China); Yang, Jun [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Department of Orthopaedics, 421 Hospital of PLA, Guangzhou 510318 (China); Dong, Weiqiang [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Department of Orthopaedics, The First Affiliated Hospital to Guangzhou Medical University, Guangzhou 510120 (China); Wang, Shengnan; Cheng, Yirong; Al-Qwbani, Mohammed [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China); Wang, Qiang, E-mail: 1780468505@qq.com [Department of Orthopaedics, Subei People’s Hospital of Jiangsu Province (Clinical Medical College of Yangzhou University), Yangzhou, Jiangsu Province 225001 (China); Yu, Bin, E-mail: carryzhang1985@live.com [Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou 510515 (China)

    2014-07-18

    Highlights: • Celecoxib has no effects on TDSCs cell proliferation in various concentrations. • Celecoxib reduced mRNAs levels of tendon associated transcription factor. • Celecoxib reduced mRNAs levels of main tendon associated collagen. • Celecoxib reduced mRNAs levels of tendon associated molecules. - Abstract: NSAIDs are often ingested to reduce the pain and improve regeneration of tendon after tendon injury. Although the effects of NSAIDs in tendon healing have been reported, the data and conclusions are not consistent. Recently, tendon-derived stem cells (TDSCs) have been isolated from tendon tissues and has been suggested involved in tendon repair. Our study aims to determine the effects of COX-2 inhibitor (celecoxib) on the proliferation and tenocytic differentiation of TDSCs. TDSCs were isolated from mice Achilles tendon and exposed to celecoxib. Cell proliferation rate was investigated at various concentrations (0.1, 1, 10 and 100 μg/ml) of celecoxib by using hemocytometer. The mRNA expression of tendon associated transcription factors, tendon associated collagens and tendon associated molecules were determined by reverse transcription-polymerase chain reaction. The protein expression of Collagen I, Collagen III, Scleraxis and Tenomodulin were determined by Western blotting. The results showed that celecoxib has no effects on TDSCs cell proliferation in various concentrations (p > 0.05). The levels of most tendon associated transcription factors, tendon associated collagens and tendon associated molecules genes expression were significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). Collagen I, Collagen III, Scleraxis and Tenomodulin protein expression were also significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). In conclusion, celecoxib inhibits tenocytic differentiation of tendon-derived stem cells but has no effects on cell proliferation.

  10. Effects of celecoxib on proliferation and tenocytic differentiation of tendon-derived stem cells

    International Nuclear Information System (INIS)

    Zhang, Kairui; Zhang, Sheng; Li, Qianqian; Yang, Jun; Dong, Weiqiang; Wang, Shengnan; Cheng, Yirong; Al-Qwbani, Mohammed; Wang, Qiang; Yu, Bin

    2014-01-01

    Highlights: • Celecoxib has no effects on TDSCs cell proliferation in various concentrations. • Celecoxib reduced mRNAs levels of tendon associated transcription factor. • Celecoxib reduced mRNAs levels of main tendon associated collagen. • Celecoxib reduced mRNAs levels of tendon associated molecules. - Abstract: NSAIDs are often ingested to reduce the pain and improve regeneration of tendon after tendon injury. Although the effects of NSAIDs in tendon healing have been reported, the data and conclusions are not consistent. Recently, tendon-derived stem cells (TDSCs) have been isolated from tendon tissues and has been suggested involved in tendon repair. Our study aims to determine the effects of COX-2 inhibitor (celecoxib) on the proliferation and tenocytic differentiation of TDSCs. TDSCs were isolated from mice Achilles tendon and exposed to celecoxib. Cell proliferation rate was investigated at various concentrations (0.1, 1, 10 and 100 μg/ml) of celecoxib by using hemocytometer. The mRNA expression of tendon associated transcription factors, tendon associated collagens and tendon associated molecules were determined by reverse transcription-polymerase chain reaction. The protein expression of Collagen I, Collagen III, Scleraxis and Tenomodulin were determined by Western blotting. The results showed that celecoxib has no effects on TDSCs cell proliferation in various concentrations (p > 0.05). The levels of most tendon associated transcription factors, tendon associated collagens and tendon associated molecules genes expression were significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). Collagen I, Collagen III, Scleraxis and Tenomodulin protein expression were also significantly decreased in celecoxib (10 μg/ml) treated group (p < 0.05). In conclusion, celecoxib inhibits tenocytic differentiation of tendon-derived stem cells but has no effects on cell proliferation

  11. Comparative anatomy of rabbit and human achilles tendons with magnetic resonance and ultrasound imaging.

    Science.gov (United States)

    Doherty, Geoffrey P; Koike, Yoichi; Uhthoff, Hans K; Lecompte, Martin; Trudel, Guy

    2006-02-01

    We sought to describe the comparative anatomy of the Achilles tendon in rabbits and humans by using macroscopic observation, magnetic resonance imaging, and ultrasonography. The calcaneus-Achilles tendon-gastrocnemius-soleus complexes from 18 New Zealand white rabbits underwent ultrasound (US) and magnetic resonance (MR) imaging and gross anatomic sectioning; these results were compared with those from a cadaveric gastrocnemius-soleus-Achilles tendon-calcaneus specimen from a 68-y-old human male. The medial and lateral gastrocnemius muscle tendons merged 5.2 +/- 0.6 mm proximal to the calcaneal insertion macroscopically, at 93% of their course, different from the gastrocnemius human tendons, which merged at 23% of their overall course. The rabbit flexor digitorum superficialis tendon, corresponding to the flexor digitorum longus tendon in human and comparable in size with the gastrocnemius tendons, was located medial and anterior to the medial gastrocnemius tendon proximally and rotated dorsally and laterally to run posterior to the Achilles tendon-calcaneus insertion. In humans, the flexor digitorum longus tendon tracks posteriorly to the medial malleolus. The soleus muscle and tendon are negligible in the rabbit; these particular comparative anatomic features in the rabbit were confirmed on the MR images. Therefore the rabbit Achilles tendon shows distinctive gross anatomical and MR imaging features that must be considered when using the rabbit as a research model, especially for mechanical testing, or when generalizing results from rabbits to humans.

  12. Biomechanical and histologic comparison of Achilles tendon ruptures reinforced with intratendinous and peritendinous plantaris tendon grafts in rabbits: an experimental study.

    Science.gov (United States)

    Ilhami, Kuru; Gokhan, Maralcan; Ulukan, Inan; Eray, Bozan M; Levent, Altinel; Ciğdem, Tokyol

    2004-11-01

    We hypothesized that the closer the reinforcing graft was to the repair zone, the more strength the healed tendon would achieved. Therefore, we compared the ruptured rabbit Achilles tendons reinforced with intratendinous and peritendinous plantaris grafts. The experimental study was performed on Achilles tendons of 20 rabbits. First, they were divided into two groups: group I (n=10) underwent intratendinous graft and end-to-end tenorraphy, and group P (n=10) were repaired end-to-end and then reinforced with a peritendinous plantaris graft. An above-knee cast was applied during 6 weeks postoperatively. The two groups were compared to each other biomechanically and histologically. Seven randomly selected rabbits from each group were used for biomechanical evaluation. The remaining six rabbits (three from each group) were used for histologic comparison. Non-operated sides (n=20) served as the control group. The mean maximum load at rupture of the repaired and control groups was 159.9+/-31 N, 83+/-7.5 N, and 207.5+/-35 N for group I, group P, and the control group, respectively. Values between groups were significantly different considering maximum load and absorbed energy to rupture. There was no significant difference between groups I and P in respect to strain. Control group tendons (groups I-C and P-C) had significantly more lengthening capability than operated tendons. Macroscopically, group I tendons were thicker and stiffer than group P tendons. Histologically, differences between the group I and group P specimens revealed that the healing process was faster in tendons augmented intratendinously. In reinforcing Achilles tendon repair, the site of the tendon graft affected the result. When the graft was used intratendinously, the healed tendon was more similar biomechanically to normal tendon and had more graft-tendon orientation histologically than the tendon augmented peritendinously.

  13. Anatomical feasibility study of flexor hallucis longus transfer in treatment of Achilles tendon and posteromedial portal of ankle arthroscopy.

    Science.gov (United States)

    Mao, Haijiao; Wang, Linger; Dong, Wenwei; Liu, Zhenxin; Yin, Weigang; Xu, Dachuan; Wapner, Keith L

    2018-04-16

    The aim of this study was to evaluate the occurrence of anatomical variations of the musculotendinous junction of the flexor hallucis longus (FHL) muscle, the relationship between FHL tendon or muscle and the tibial neurovascular bundle at the level of the posterior ankle joint in human cadavers. Seventy embalmed feet from 20 male and 15 female cadavers, the cadavers' mean age was 65.4 (range from 14 to 82) years, were dissected and anatomically classified to observe FHL muscle morphology define the relationship between FHL tendon or muscle and the tibial neurovascular bundle. The distance between the musculotendinous junction and the relationship between FHL tendon or muscle and the tibial neurovascular bundle was determined. Three morphology types of FHL muscle were identified: a long lateral and shorter medial muscle belly, which was observed in 63 specimens (90%); equal length medial and lateral muscle bellies, this variant was only observed in five specimens (7.1%); one lateral and no medial muscle belly, which was observed in two specimens (2.9%). No statistically significant difference was observed according to gender or side (p > 0.05). Two patterns were identified and described between FHL tendon or muscle and the tibial neurovascular bundle. Pattern 1, the distance between the neurovascular bundle and FHL tendon was 3.46 mm (range 2.34-8.84, SD = 2.12) which was observed in 66 specimens (94.3%); Pattern 2, there was no distance which was observed in four specimens (5.7%). Knowing FHL muscle morphology, variations provide new important insights into secure planning and execution of a FHL transfer for Achilles tendon defect as well as for the interpretation of ultrasound and magnetic resonance images. With posterior arthroscopic for the treatment of various ankle pathologies, posteromedial portal may be introduced into the posterior aspect of the ankle without gross injury to the tibial neurovascular structures because of the gap between the

  14. Effects of Volar Tilt, Wrist Extension, and Plate Position on Contact Between Flexor Pollicis Longus Tendon and Volar Plate.

    Science.gov (United States)

    Wurtzel, Caroline N Wolfe; Burns, Geoffrey T; Zhu, Andy F; Ozer, Kagan

    2017-12-01

    Volar plates positioned at, or distal to, the watershed line have been shown to have a higher incidence of attritional rupture of the flexor pollicis longus (FPL). In this study, we aimed to evaluate the effect of wrist extension and volar tilt on the contact between the plate and the FPL tendon in a cadaver model. We hypothesized that, following volar plate application, loss of native volar tilt increases the contact between the FPL and the plate at lower degrees of wrist extension. A volar locking plate was applied on 6 fresh-frozen cadavers. To determine the contact between the plate and the FPL tendon, both structures were wrapped with copper wire and circuit conductivity was monitored throughout wrist motion. A lateral wrist radiograph was obtained at each circuit closure, indicating tendon-plate contact. Baseline measurements were obtained with plate positioned at Soong grades 0, 1, and 2. An extra-articular osteotomy was made and contact was recorded at various volar tilt angles (+5°, 0°, -5°, -10°, -15°, and -20°) in 3 different plate positions. A blinded observer measured the degree of wrist extension on all lateral radiographs. Data were analyzed using linear mixed-effects regression model. Plates placed distal to the watershed line had the most contact throughout wrist range of motion. Significantly, less wrist extension was required for contact in wrists with neutral or dorsal tilt and in distally placed volar plates. Volar tilt, wrist extension, and plate position were 3 independent risk factors determining contact between plate and tendon. Loss of volar tilt, increased wrist extension, and higher Soong grade plate position result in greater contact between wire-wrapped FPL tendon and plate. The FPL/plate contact chart generated in this study may be used to assess the risk of rupture in the clinical setting. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  15. MR imaging of delamination tears of the rotator cuff tendons

    International Nuclear Information System (INIS)

    Walz, Daniel M.; Chen, Steven; Miller, Theodore T.; Hofman, Josh

    2007-01-01

    The objective was to describe the imaging appearances and location of delamination tears of the rotator cuff tendons on non-contrast conventional MR imaging. This study was reviewed and approved by our Institutional Review Board. The reports of 548 consecutive MR examinations of the shoulder were reviewed, looking for mention or description of delamination tears of the rotator cuff. The images of the identified cases were then reviewed by two radiologists to confirm the findings. Correlation with surgical and arthroscopic information was then performed. Delamination tears were defined as horizontal retraction of either the bursal or articular surface of the tendon, manifest as thickening of the torn retracted edge, and/or interstitial splitting of the tendon, manifest as fluid-like high signal intensity on fat-suppressed T2-weighted oblique coronal images. Fourteen cases of delamination tears were identified in 13 patients. Ten of the cases involved the supraspinatus tendon, all with articular surface involvement. Nine of these supraspinatus cases were isolated tears and one occurred as part of a full thickness tear. All 10 of these supraspinatus cases showed medial retraction of the articular surface of the tendon, with thickening of the retracted edge, and 5 of the 10 had a demonstrable horizontal cleft in the interstitium. Four cases involved the subscapularis tendon, with articular surface disruption in three and pure interstitial delamination in one. Medial subluxation of the tendon of the long head of the biceps was present in all four cases. No delamination tears occurred on the bursal surface. Only three of the 14 shoulders underwent surgical repair with one confirmation of supraspinatus delamination, one confirmation of a subscapularis tear that had become a full thickness tear 10 months after initial imaging and another interstitial subscapularis delamination that was not identified arthroscopically. Delamination tears occur most often in the

  16. MR imaging of delamination tears of the rotator cuff tendons

    Energy Technology Data Exchange (ETDEWEB)

    Walz, Daniel M.; Chen, Steven [North Shore University Hospital, Department of Radiology, Manhasset, NY (United States); Miller, Theodore T. [Hospital for Special Surgery, Department of Radiology and Imaging, New York, NY (United States); Hofman, Josh [Long Island Jewish Medical Center, New Hyde Park, NY (United States)

    2007-05-15

    The objective was to describe the imaging appearances and location of delamination tears of the rotator cuff tendons on non-contrast conventional MR imaging. This study was reviewed and approved by our Institutional Review Board. The reports of 548 consecutive MR examinations of the shoulder were reviewed, looking for mention or description of delamination tears of the rotator cuff. The images of the identified cases were then reviewed by two radiologists to confirm the findings. Correlation with surgical and arthroscopic information was then performed. Delamination tears were defined as horizontal retraction of either the bursal or articular surface of the tendon, manifest as thickening of the torn retracted edge, and/or interstitial splitting of the tendon, manifest as fluid-like high signal intensity on fat-suppressed T2-weighted oblique coronal images. Fourteen cases of delamination tears were identified in 13 patients. Ten of the cases involved the supraspinatus tendon, all with articular surface involvement. Nine of these supraspinatus cases were isolated tears and one occurred as part of a full thickness tear. All 10 of these supraspinatus cases showed medial retraction of the articular surface of the tendon, with thickening of the retracted edge, and 5 of the 10 had a demonstrable horizontal cleft in the interstitium. Four cases involved the subscapularis tendon, with articular surface disruption in three and pure interstitial delamination in one. Medial subluxation of the tendon of the long head of the biceps was present in all four cases. No delamination tears occurred on the bursal surface. Only three of the 14 shoulders underwent surgical repair with one confirmation of supraspinatus delamination, one confirmation of a subscapularis tear that had become a full thickness tear 10 months after initial imaging and another interstitial subscapularis delamination that was not identified arthroscopically. Delamination tears occur most often in the

  17. Uncovering the cellular and molecular changes in tendon stem/progenitor cells attributed to tendon aging and degeneration.

    Science.gov (United States)

    Kohler, Julia; Popov, Cvetan; Klotz, Barbara; Alberton, Paolo; Prall, Wolf Christian; Haasters, Florian; Müller-Deubert, Sigrid; Ebert, Regina; Klein-Hitpass, Ludger; Jakob, Franz; Schieker, Matthias; Docheva, Denitsa

    2013-12-01

    Although the link between altered stem cell properties and tissue aging has been recognized, the molecular and cellular processes of tendon aging have not been elucidated. As tendons contain stem/progenitor cells (TSPC), we investigated whether the molecular and cellular attributes of TSPC alter during tendon aging and degeneration. Comparing TSPC derived from young/healthy (Y-TSPC) and aged/degenerated human Achilles tendon biopsies (A-TSPC), we observed that A-TSPC exhibit a profound self-renewal and clonogenic deficits, while their multipotency was still retained. Senescence analysis showed a premature entry into senescence of the A-TSPC, a finding accompanied by an upregulation of p16(INK4A). To identify age-related molecular factors, we performed microarray and gene ontology analyses. These analyses revealed an intriguing transcriptomal shift in A-TSPC, where the most differentially expressed probesets encode for genes regulating cell adhesion, migration, and actin cytoskeleton. Time-lapse analysis showed that A-TSPC exhibit decelerated motion and delayed wound closure concomitant to a higher actin stress fiber content and a slower turnover of actin filaments. Lastly, based on the expression analyses of microarray candidates, we suggest that dysregulated cell-matrix interactions and the ROCK kinase pathway might be key players in TSPC aging. Taken together, we propose that during tendon aging and degeneration, the TSPC pool is becoming exhausted in terms of size and functional fitness. Thus, our study provides the first fundamental basis for further exploration into the molecular mechanisms behind tendon aging and degeneration as well as for the selection of novel tendon-specific therapeutical targets. © 2013 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  18. A new barbed device for repair of flexor tendons.

    LENUS (Irish Health Repository)

    Hirpara, K M

    2012-02-01

    We split 100 porcine flexor tendons into five groups of 20 tendons for repair. Three groups were repaired using the Pennington modified Kessler technique, the cruciate or the Savage technique, one using one new device per tendon and the other with two new devices per tendon. Half of the tendons received supplemental circumferential Silfverskiold type B cross-stitch. The repairs were loaded to failure and a record made of their bulk, the force required to produce a 3 mm gap, the maximum force applied before failure and the stiffness. When only one device was used repairs were equivalent to the Pennington modified Kessler for all parameters except the force to produce a 3 mm gap when supplemented with a circumferential repair, which was equivalent to the cruciate. When two devices were used the repair strength was equivalent to the cruciate repair, and when the two-device repair was supplemented with a circumferential suture the force to produce a 3 mm gap was equivalent to that of the Savage six-strand technique.

  19. Changes in tendon spatial frequency parameters with loading.

    Science.gov (United States)

    Pearson, Stephen J; Engel, Aaron J; Bashford, Gregory R

    2017-05-24

    To examine and compare the loading related changes in micro-morphology of the patellar tendon. Fifteen healthy young males (age 19±3yrs, body mass 83±5kg) were utilised in a within subjects matched pairs design. B mode ultrasound images were taken in the sagittal plane of the patellar tendon at rest with the knee at 90° flexion. Repeat images were taken whilst the subjects were carrying out maximal voluntary isometric contractions. Spatial frequency parameters related to the tendon morphology were determined within regions of interest (ROI) from the B mode images at rest and during isometric contractions. A number of spatial parameters were observed to be significantly different between resting and contracted images (Peak spatial frequency radius (PSFR), axis ratio, spatial Q-factor, PSFR amplitude ratio, and the sum). These spatial frequency parameters were indicative of acute alterations in the tendon micro-morphology with loading. Acute loading modifies the micro-morphology of the tendon, as observed via spatial frequency analysis. Further research is warranted to explore its utility with regard to different loading induced micro-morphological alterations, as these could give valuable insight not only to aid strengthening of this tissue but also optimization of recovery from injury and treatment of conditions such as tendinopathies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Nonlinear model for viscoelastic behavior of Achilles tendon.

    Science.gov (United States)

    Kahn, Cyril J F; Wang, Xiong; Rahouadj, Rachid

    2010-11-01

    Although the mechanical properties of ligament and tendon are well documented in research literature, very few unified mechanical formulations can describe a wide range of different loadings. The aim of this study was to propose a new model, which can describe tendon responses to various solicitations such as cycles of loading, unloading, and reloading or successive relaxations at different strain levels. In this work, experiments with cycles of loading and reloading at increasing strain level and sequences of relaxation were performed on white New Zealand rabbit Achilles tendons. We presented a local formulation of thermodynamic evolution outside equilibrium at a representative element volume scale to describe the tendon's macroscopic behavior based on the notion of relaxed stress. It was shown that the model corresponds quite well to the experimental data. This work concludes with the complexity of tendons' mechanical properties due to various microphysical mechanisms of deformation involved in loading such as the recruitment of collagen fibers, the rearrangement of the microstructure (i.e., collagens type I and III, proteoglycans, and water), and the evolution of relaxed stress linked to these mechanisms.

  1. Button fixation technique for Achilles tendon reinsertion: a biomechanical study.

    Science.gov (United States)

    Awogni, David; Chauvette, Guillaume; Lemieux, Marie-Line; Balg, Frédéric; Langelier, Ève; Allard, Jean-Pascal

    2014-01-01

    Chronic insertional tendinopathy of the Achilles tendon is a frequent and disabling pathologic entity. Operative treatment is indicated for patients for whom nonoperative management has failed. The treatment can consist of the complete detachment of the tendon insertion and extensive debridement. We biomechanically tested a new operative technique that uses buttons for fixation of the Achilles tendon insertion on the posterior calcaneal tuberosity and compared it with 2 standard bone anchor techniques. A total of 40 fresh-frozen cadaver specimens were used to compare 3 fixation techniques for reinserting the Achilles tendon: single row anchors, double row anchors, and buttons. The ultimate loads and failure mechanisms were recorded. The button assembly (median load 764 N, range 713 to 888) yielded a median fixation strength equal to 202% (range 137% to 251%) of that obtained with the double row anchors (median load 412 N, range 301 to 571) and 255% (range 213% to 317%) of that obtained with the single row anchors (median load 338 N, range 241 to 433N). The most common failure mechanisms were suture breakage with the buttons (55%) and pull out of the implant with the double row (70%) and single row (85%) anchors. The results of the present biomechanical cadaver study have shown that Achilles tendon reinsertion fixation using the button technique provides superior pull out strength than the bone anchors tested. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  2. An investigation of tendon sheathing filler migration into concrete

    International Nuclear Information System (INIS)

    Naus, D.J.; Oland, C.B.

    1998-03-01

    During some of the inspections at nuclear power plants with prestressed concrete containments, it was observed that the containments has experienced leakage of the tendon sheathing filler (i.e., streaks). The objective of this activity was to provide an indication of the extent of tendon sheathing filler leakage into the concrete and its affects on concrete properties. Literature was reviewed and concrete core samples were obtained from the Trojan Nuclear Plant and tested. The literature primarily addressed effects of crude or lubricating oils that are known to cause concrete damage. However, these materials have significantly different characteristics relative to the materials used as tendon sheathing fillers. Examination and testing of the concrete cores indicated that the appearance of tendon sheathing filler on the concrete surface was due to leakage from the conduits and its subsequent migration through cracks that were present. Migration of the tendon sheathing filler was confined to the cracks and there was no perceptible movement into the concrete. Results of compressive strength testing indicated that the concrete quality was consistent in the containment and that the strength had increased over 40% in 25.4 years relative to the average compressive strength at 28-days age

  3. Effect of aging and exercise on the tendon

    DEFF Research Database (Denmark)

    Svensson, Rene B; Heinemeier, Katja Maria; Couppé, Christian

    2016-01-01

    Here, we review the literature on how tendons respond and adapt to ageing and exercise. With respect to aging, there are considerable changes early in life, but this seems to be maturation rather than aging per se. In vitro data indicate that aging is associated with a decreased potential for cel...... and modulus of the tendon and may reduce the amount of glycation. Exercise thereby tends to counteract the effects of aging.......Here, we review the literature on how tendons respond and adapt to ageing and exercise. With respect to aging, there are considerable changes early in life, but this seems to be maturation rather than aging per se. In vitro data indicate that aging is associated with a decreased potential for cell...... glycation-derived cross-links increase substantially. Mechanically, aging appears to be associated with a reduction in modulus and strength. With respect to exercise, tendon cells respond by producing growth factors, and there is some support for a loading-induced increase in tendon collagen synthesis...

  4. Mechanoactive scaffold induces tendon remodeling and expression of fibrocartilage markers.

    Science.gov (United States)

    Spalazzi, Jeffrey P; Vyner, Moira C; Jacobs, Matthew T; Moffat, Kristen L; Lu, Helen H

    2008-08-01

    Biological fixation of soft tissue-based grafts for anterior cruciate ligament (ACL) reconstruction poses a major clinical challenge. The ACL integrates with subchondral bone through a fibrocartilage enthesis, which serves to minimize stress concentrations and enables load transfer between two distinct tissue types. Functional integration thus requires the reestablishment of this fibrocartilage interface on reconstructed ACL grafts. We designed and characterized a novel mechanoactive scaffold based on a composite of poly-alpha-hydroxyester nanofibers and sintered microspheres; we then used the scaffold to test the hypothesis that scaffold-induced compression of tendon grafts would result in matrix remodeling and the expression of fibrocartilage interface-related markers. Histology coupled with confocal microscopy and biochemical assays were used to evaluate the effects of scaffold-induced compression on tendon matrix collagen distribution, cellularity, proteoglycan content, and gene expression over a 2-week period. Scaffold contraction resulted in over 15% compression of the patellar tendon graft and upregulated the expression of fibrocartilage-related markers such as Type II collagen, aggrecan, and transforming growth factor-beta3 (TGF-beta3). Additionally, proteoglycan content was higher in the compressed tendon group after 1 day. The data suggest the potential of a mechanoactive scaffold to promote the formation of an anatomic fibrocartilage enthesis on tendon-based ACL reconstruction grafts.

  5. Effects of aging and resistance training in rat tendon remodeling.

    Science.gov (United States)

    Marqueti, Rita C; Durigan, João L Q; Oliveira, Anderson José S; Mekaro, Marcelo Shinyu; Guzzoni, Vinicius; Aro, Andrea A; Pimentel, Edson Rosa; Selistre-de-Araujo, Heloisa S

    2018-01-01

    In elderly persons, weak tendons contribute to functional limitations, injuries, and disability, but resistance training can attenuate this age-related decline. We evaluated the effects of resistance training on the extracellular matrix (ECM) of the calcaneal tendon (CT) in young and old rats and its effect on tendon remodeling. Wistar rats aged 3 mo (young, n = 30) and 20 mo (old, n = 30) were divided into 4 groups: young sedentary, young trained, old sedentary (OS), and old trained (OT). The training sessions were conducted over a 12-wk period. Aging in sedentary rats showed down-regulation in key genes that regulated ECM remodeling. Moreover, the OS group showed a calcification focus in the distal region of the CT, with reduced blood vessel volume density. In contrast, resistance training was effective in up-regulating connective tissue growth factor, VEGF, and decorin gene expression in old rats. Resistance training also increased proteoglycan content in young and old rats in special small leucine-rich proteoglycans and blood vessels and prevented calcification in OT rats. These findings confirm that resistance training is a potential mechanism in the prevention of aging-related loss in ECM and that it attenuates the detrimental effects of aging in tendons, such as ruptures and tendinopathies.-Marqueti, R. C., Durigan, J. L. Q., Oliveira, A. J. S., Mekaro, M. S., Guzzoni, V., Aro, A. A., Pimentel, E. R., Selistre-de-Araujo, H. S. Effects of aging and resistance training in rat tendon remodeling. © FASEB.

  6. Genetics Home Reference: hereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis

    Science.gov (United States)

    ... Hereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis Printable PDF Open All Close All Enable Javascript ... Fibrosing Poikiloderma with Tendon Contractures, Myopathy, and Pulmonary ... Lung, and Blood Institute (NHLBI): Pulmonary Function Tests National ...

  7. The adaptability of tendon to loading differs in men and women

    DEFF Research Database (Denmark)

    Magnusson, Peter S; Hansen, Philip; Langberg, Henning

    2007-01-01

    The reason why women sustain more soft tissue injury than men during physical activity is unknown. Connective tissue properties and extracellular matrix adaptability in human tendon were investigated in models that addressed biochemical, physiological and biomechanical aspects of tendon connectiv...

  8. Diclofenac Patch for Treatment of Mild to Moderate Tendonitis or Bursitis

    Science.gov (United States)

    2008-08-05

    Rotator Cuff Tendonitis; Bicipital Tendonitis; Subdeltoid Bursitis of the Shoulder; Subacromial Bursitis of the Shoulder; Medial Epicondylitis of the Elbow; Lateral Epicondylitis of the Elbow; DeQuervain's Tenosynovitis of the Wrist

  9. MOLECULAR PATHOBIOLOGICAL AND SCANNING ELECTRON MICROSCOPIC CHANGES IN HORSE TENDON CELLS TREA TED WITH ENROFLOXACIN

    Directory of Open Access Journals (Sweden)

    A. Khan1 and J. Halper

    2003-12-01

    Full Text Available Fluoroquinolone (FQNL antibiotics have been used widely in horses because of their broad-spectrum bactericidal activity and relative safety, however, their use is not without risk. Tendonitis and spontaneous tendon rupture have been reported in people during or following therapy with FQNLs. To evaluate the potential damage of enrofloxacin (ENRO on the equine superficial digital flexor tendon (SOFT, an equine cell culture system as an in vitro model of equine tendon injury and repair was developed. The effects of ENRO on tendon cell cultures established from equine SOFT were studied. The data thus collected demonstrated that ENRO inhibited cell proliferation, induced morphological changes and altered proteoglycan synthesis in equine tendon cell cultures. Interestingly, these effects were more pronounced in juvenile tendon cells as compared to adult horses, It. is hypothesized that morphological changes and inhibition of cell proliferation is a result of impaired production of proteoglycans and other glycoproteins in the extracellular matrix of ENRO-treated tendon cells.

  10. Loss of Drosophila A-type lamin C initially causes tendon abnormality including disintegration of cytoskeleton and nuclear lamina in muscular defects.

    Science.gov (United States)

    Uchino, Ryo; Nonaka, Yu-Ki; Horigome, Tuneyoshi; Sugiyama, Shin; Furukawa, Kazuhiro

    2013-01-01

    Lamins are the major components of nuclear envelope architecture, being required for both the structural and informational roles of the nuclei. Mutations of lamins cause a spectrum of diseases in humans, including muscular dystrophy. We report here that the loss of the A-type lamin gene, lamin C in Drosophila resulted in pupal metamorphic lethality caused by tendon defects, matching the characteristics of human A-type lamin revealed by Emery-Dreifuss muscular dystrophy (EDMD). In tendon cells lacking lamin C activity, overall cell morphology was affected and organization of the spectraplakin family cytoskeletal protein Shortstop which is prominently expressed in tendon cells gradually disintegrated, notably around the nucleus and in a manner correlating well with the degradation of musculature. Furthermore, lamin C null mutants were efficiently rescued by restoring lamin C expression to shortstop-expressing cells, which include tendon cells but exclude skeletal muscle cells. Thus the critical function of A-type lamin C proteins in Drosophila musculature is to maintain proper function and morphology of tendon cells. Copyright © 2012 Elsevier Inc. All rights reserved.

  11. Exercise following a short immobilization period is detrimental to tendon properties and joint mechanics in a rat rotator cuff injury model.

    Science.gov (United States)

    Peltz, Cathryn D; Sarver, Joseph J; Dourte, Leann M; Würgler-Hauri, Carola C; Williams, Gerald R; Soslowsky, Louis J

    2010-07-01

    Rotator cuff tears are a common clinical problem that can result in pain and disability. Previous studies in a rat model showed enhanced tendon to bone healing with postoperative immobilization. The objective of this study was to determine the effect of postimmobilization activity level on insertion site properties and joint mechanics in a rat model. Our hypothesis was that exercise following a short period of immobilization will cause detrimental changes in insertion site properties compared to cage activity following the same period of immobilization, but that passive shoulder mechanics will not be affected. We detached and repaired the supraspinatus tendon of 22 Sprague-Dawley rats, and the injured shoulder was immobilized postoperatively for 2 weeks. Following immobilization, rats were prescribed cage activity or exercise for 12 weeks. Passive shoulder mechanics were determined, and following euthanasia, tendon cross-sectional area and mechanical properties were measured. Exercise following immobilization resulted in significant decreases compared to cage activity in range of motion, tendon stiffness, modulus, percent relaxation, and several parameters from both a structurally based elastic model and a quasi-linear viscoelastic model. Therefore, we conclude that after a short period of immobilization, increased activity is detrimental to both tendon mechanical properties and shoulder joint mechanics, presumably due to increased scar production. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

  12. MRI of the Achilles tendon: A comprehensive review of the anatomy, biomechanics, and imaging of overuse tendinopathies

    Energy Technology Data Exchange (ETDEWEB)

    Pierre-Jerome, Claude; Moncayo, Valeria; Terk, Michael R. (Dept. of Radiology, Emory Univ. Orthopedics and Spine Center, Atlanta, GA (United States)), e-mail: cpierr3@emory.edu

    2010-05-15

    The Achilles tendon is the largest tendon in the body; it plays an important role in the biomechanics of the lower extremity. It can withstand great forces, especially during sporting exercises and pivoting. The pathologies related to the Achilles tendon are diverse and many carry undesirable consequences. We retrospectively analyzed the images of patients who underwent examinations of the ankle/foot region to review the anatomy of the Achilles tendon and its surroundings and to search for pathologies consistent with overuse injuries. The anatomy of the tendon is described from origin to insertion. The imaging characteristics of the Achilles tendon including pitfalls are reviewed. We also describe the Achilles overuse injuries: paratenonitis, tendinosis, tendon tear, atypical tear, tendon re-tear, retrocalcaneal bursitis, retro-Achilles bursitis, Haglund's deformity, and tendon calcification. We present other entities like tendon ossification and failed transplanted Achilles tendon, with emphasis on MRI

  13. MRI of the Achilles tendon: A comprehensive review of the anatomy, biomechanics, and imaging of overuse tendinopathies

    International Nuclear Information System (INIS)

    Pierre-Jerome, Claude; Moncayo, Valeria; Terk, Michael R.

    2010-01-01

    The Achilles tendon is the largest tendon in the body; it plays an important role in the biomechanics of the lower extremity. It can withstand great forces, especially during sporting exercises and pivoting. The pathologies related to the Achilles tendon are diverse and many carry undesirable consequences. We retrospectively analyzed the images of patients who underwent examinations of the ankle/foot region to review the anatomy of the Achilles tendon and its surroundings and to search for pathologies consistent with overuse injuries. The anatomy of the tendon is described from origin to insertion. The imaging characteristics of the Achilles tendon including pitfalls are reviewed. We also describe the Achilles overuse injuries: paratenonitis, tendinosis, tendon tear, atypical tear, tendon re-tear, retrocalcaneal bursitis, retro-Achilles bursitis, Haglund's deformity, and tendon calcification. We present other entities like tendon ossification and failed transplanted Achilles tendon, with emphasis on MRI

  14. Application of Time Delay Consideration on Bridge Vibration Control Method with Active Tendons

    Directory of Open Access Journals (Sweden)

    Lezin Seba MINSILI

    2010-12-01

    Full Text Available For many years bridge structures have been designed or constructed as passive structures that rely on their mass and solidity to resist external forces, while being incapable of adapting to the dynamics of an ever-changing environment. When the rigidity assumption is not met in particular for high-rise structures like bridge towers, a proper dynamic model should be established and conclusions made on the differential vibration of the tower when it is investigated out of the bridge system. The present work outlines a vibration control method by tendons on the tower of cable supported structures considering time delay effects, based on the discrete-time Linearization of the Feedback Gain Matrix. The efficiency of this vibration control method first proposed on the design process of a local bridge in Cameroon, is more compatible to the control of civil structures and is of great interest in accordance with simulation results.

  15. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium.

    Science.gov (United States)

    Streit, Jonathan J; Shishani, Yousef; Rodgers, Mark; Gobezie, Reuben

    2015-01-01

    Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB) tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon and synovial sheath in order to compare those findings to known histologic changes seen in other tendinopathies. Twenty-six consecutive patients (mean age 45.4±13.7 years) underwent an open subpectoral biceps tenodesis for anterior shoulder pain localized to the bicipital groove. Excised tendons were sent for histologic analysis. Specimens were graded using a semiquantitative scoring system to evaluate tenocyte morphology, the presence of ground substance, collagen bundle characteristics, and vascular changes. Chronic inflammation was noted in only two of 26 specimens, and no specimen demonstrated acute inflammation. Tenocyte enlargement and proliferation, characterized by increased roundness and size of the cell and nucleus with proteoglycan matrix expansion and myxoid degenerative changes, was found in all 26 specimens. Abundant ground substance, collagen bundle changes, and increased vascularization were visualized in all samples. Anterior shoulder pain attributed to the biceps tendon does not appear to be due to an inflammatory process in most cases. The histologic findings of the extra-articular portion of the LHB tendon and synovial sheath are similar to the pathologic findings in de Quervain tenosynovitis at the wrist, and may be due to a chronic degenerative process similar to this and other tendinopathies of the body.

  16. Validity and Reliability of the Achilles Tendon Total Rupture Score

    DEFF Research Database (Denmark)

    Ganestam, Ann; Barfod, Kristoffer; Klit, Jakob

    2013-01-01

    study was to validate a Danish translation of the ATRS. The ATRS was translated into Danish according to internationally adopted standards. Of 142 patients, 90 with previous rupture of the Achilles tendon participated in the validity study and 52 in the reliability study. The ATRS showed moderately......The best treatment of acute Achilles tendon rupture remains debated. Patient-reported outcome measures have become cornerstones in treatment evaluations. The Achilles tendon total rupture score (ATRS) has been developed for this purpose but requires additional validation. The purpose of the present...... = .07). The limits of agreement were ±18.53. A strong correlation was found between test and retest (intercorrelation coefficient .908); the standard error of measurement was 6.7, and the minimal detectable change was 18.5. The Danish version of the ATRS showed moderately strong criterion validity...

  17. Could Ossification of the Achilles Tendon Have a Hereditary Component?

    Directory of Open Access Journals (Sweden)

    Chawki Cortbaoui

    2013-01-01

    Full Text Available Ossification of the Achilles tendon (OTA is an unusual clinical condition. It is characterized by the presence of an ossified mass within the fibrocartilaginous substance of the Achilles tendon. The etiology of the ossification of the Achilles tendon is unknown. Review of the literature suggests that its etiology is multifactorial. The major contributing factors are trauma and surgery with other minor causes such as systemic diseases, metabolic conditions, and infections. To our knowledge, no previous reports suggest any genetic/hereditary predisposition in OAT. We report 3 siblings who have OAT with no history of any of the aforementioned predisposing factors. Could OAT have a hereditary component as one of its etiologies?

  18. PRP as an Adjunct to Rotator Cuff Tendon Repair.

    Science.gov (United States)

    Barber, F Alan

    2018-06-01

    Arthroscopic rotator cuff repair is a commonly performed repair. Technical developments provide surgeons the tools to create biomechanically robust repairs. How can the biological response mirror the strong and stable surgery? Platelet-rich plasma (PRP) is a supraphysiological platelet concentration which may positively augment rotator cuff healing. Not all PRPs are the same. High leukocyte levels and thrombin activation may be detrimental to tendon healing. Thrombin activation triggers an immediate release of growth factors and may actually inhibit some parts of the healing response. Clear differences exist between liquid PRP (products released within hours after activation) and solid fibrin PRP which slowly releases factors over days. The heterogenicity data and grouping liquid and solid PRP together make systematic reviews confusing. Solid PRP fibrin constructs are often associated with increased tendon healing. PRP fibrin matrix offers the greatest promise for improving clinical success after rotator cuff tendon repair.

  19. Biomechanical characteristics of the eccentric Achilles tendon exercise

    DEFF Research Database (Denmark)

    Henriksen, Marius; Aaboe, Jens; Bliddal, Henning

    2009-01-01

    that although the tendon loads are similar, the tendon is vibrated at higher frequencies during the eccentric phase than during the concentric phases. This study provides data that may explain the mechanisms behind the effectiveness of eccentric exercises used in the treatment of Achilles tendinopathies........ No differences in Achilles tendon loads were found. INTERPRETATION: This descriptive study demonstrates differences in the movement biomechanics between the eccentric and concentric phases of one-legged full weight bearing ankle dorsal and plantar flexion exercises. In particular, the findings imply......BACKGROUND: Eccentric exercise has been shown to provide good short-term clinical results in the treatment of painful mid-portion chronic Achilles tendinopathies. However, the mechanisms behind the positive effects of eccentric rehabilitation regimes are not known, and research...

  20. Surgical treatment of distal biceps tendon rupture: a case report

    Directory of Open Access Journals (Sweden)

    Cristina N. Cozma

    2017-11-01

    Full Text Available Objectives. Distal biceps tendon rupture affects the functional upperextremity movement, impairing supination and flexion strength. According to age, profession and additional risks treatment might be nonoperative or surgical. Methods. We describe the case of a 43 years old male patient who sustained an injury to his right distal biceps and was diagnosed with acute right distal biceps rupture. Surgical treatment was decided and biceps tendon was reinserted to the radius tuberosity using a combination of a cortical button fixation associated with an interference screw. Results. Postoperative functional result was favorable with no complications and with no movement limitation after one month. Conclusions. When possible, distal biceps tendon repair should be realized surgically because this permits restoring of the muscle strength to near normal levels with no loss of motion. Nerve complications are common; therefore the surgery should be realized by experienced upper extremity surgeons.

  1. Multiple Tophaceous Gout of Hand with Extensor Tendon Rupture

    Directory of Open Access Journals (Sweden)

    Haruki Tobimatsu

    2017-01-01

    Full Text Available A 45-year-old man presented with painless subcutaneous masses bilaterally on his hands and loss of motion or contracture of the fingers. Initially, drug therapy to reduce the serum uric acid was administered and was expected to reduce the tophi. However, during observation at the clinic, spontaneous rupture of an extensor tendon occurred, and surgical repair of the tendon and resection of the masses were performed. Surgical exploration of the right hand showed hypertrophic white-colored crystal deposits that both surrounded and invaded the extensor digitorum communis of the index finger, which was ruptured. Histopathologic examination of the specimen demonstrated findings consistent with gouty tophi. Tophaceous gout can induce a rupture of tendons during clinical observation, and surgical resection of the tophi might be needed to prevent ruptures.

  2. Long-term reliability evaluation of nuclear containments with tendon force degradation

    International Nuclear Information System (INIS)

    Kim, Sang-Hyo; Choi, Moon-Seock; Joung, Jung-Yeun; Kim, Kun-Soo

    2013-01-01

    Highlights: • A probabilistic model on long-term degradation of tendon force is developed. • By using the model, we performed reliability evaluation of nuclear containment. • The analysis is also performed for the case with the strict maintenance programme. • We showed how to satisfy the target safety in the containments facing life extension. - Abstract: The long-term reliability of nuclear containment is important for operating nuclear power plants. In particular, long-term reliability should be clarified when the service life of nuclear containment is being extended. This study focuses not only on determining the reliability of nuclear containment but also presenting the reliability improvement by strengthening the containment itself or by running a strict maintenance programme. The degradation characteristics of tendon force are estimated from the data recorded during in-service inspection of containments. A reliability analysis is conducted for a limit state of through-wall cracking, which is conservative, but most crucial limit state. The results of this analysis indicate that reliability is the lowest at 3/4 height of the containment wall. Therefore, this location is the most vulnerable for the specific limit state considered in this analysis. Furthermore, changes in structural reliability owing to an increase in the number of inspecting tendons are analysed for verifying the effect of the maintenance program's intensity on expected containment reliability. In the last part of this study, an example of obtaining target reliability of nuclear containment by strengthening its structural resistance is presented. A case study is conducted for exemplifying the effect of strengthening work on containment reliability, especially during extended service life

  3. Metabolic activity and collagen turnover in human tendon in response to physical activity

    DEFF Research Database (Denmark)

    Kjaer, M; Langberg, H; Miller, B F

    2005-01-01

    Connective tissue of the human tendon plays an important role in force transmission. The extracellular matrix turnover of tendon is influenced by physical activity. Blood flow, oxygen demand, and the level of collagen synthesis and matrix metalloproteinases increase with mechanical loading. Gene...... of overuse tendon injuries occurring during sport, work or leisure-related activities....

  4. The Role of Bioreactors in Ligament and Tendon Tissue Engineering.

    Science.gov (United States)

    Mace, James; Wheelton, Andy; Khan, Wasim S; Anand, Sanj

    2016-01-01

    Bioreactors are pivotal to the emerging field of tissue engineering. The formation of neotissue from pluripotent cell lineages potentially offers a source of tissue for clinical use without the significant donor site morbidity associated with many contemporary surgical reconstructive procedures. Modern bioreactor design is becoming increasingly complex to provide a both an expandable source of readily available pluripotent cells and to facilitate their controlled differentiation into a clinically applicable ligament or tendon like neotissue. This review presents the need for such a method, challenges in the processes to engineer neotissue and the current designs and results of modern bioreactors in the pursuit of engineered tendon and ligament.

  5. Supraspinatus Intramuscular Calcified Hematoma or Necrosis Associated with Tendon Tear

    Directory of Open Access Journals (Sweden)

    Alexandre Lädermann

    2015-01-01

    Full Text Available Introduction. Rotator cuff intramuscular calcification is a rare condition usually caused by heterotopic ossification and myositis ossificans. Case Presentation. We describe a patient with voluminous calcified mass entrapped in supraspinatus muscle associated with corresponding tendon tear. Histological examination corresponded to a calcified hematoma or necrosis. Patient was surgically managed with open excision of the calcified hematoma and rotator cuff arthroscopic repair. At 6 months, supraspinatus muscle was healed, and functional outcome was good. Discussion and Conclusion. We hypothesized that supraspinatus intramuscular calcified hematoma was responsible for mechanical stress on the tendon. This association has never been described.

  6. Tensile tests of 2500-kip prestressing tendons for the PCRV

    International Nuclear Information System (INIS)

    Nicolayeff, V.

    1978-05-01

    A 2500-kip (11-MN) capacity prestressing tendon consisting of sixty 0.5-in. (12.7-mm) strands was designed and tested for General Atomic Company by VSL Corporation of Los Gatos, California. Results of the static tensile test described in this report, and of dynamic tensile tests conducted by VSL in 1968 and 1969, indicate that the tendon system satisfies the requirements of the ASME Boiler and Pressure Vessel Code, Section III, Division 2, and so can be used for prestressing concrete reactor vessels

  7. Human Achilles tendon glycation and function in diabetes

    DEFF Research Database (Denmark)

    Couppe, Christian; Svensson, Rene Brüggebusch; Kongsgaard, Mads

    2016-01-01

    Diabetic patients have an increased risk of foot ulcers, and glycation of collagen may increase tissue stiffness. We hypothesized that the level of glycemic control (glycation) may affect Achilles tendon stiffness, which can influence gait pattern. We therefore investigated the relationship between...... tissue cross-linking were greater in diabetic patients compared to controls. The higher foot pressure indicates that material stiffness of tendon and other tissue (e.g skin and joint capsule) may influence on foot gait. The difference in foot pressure distribution may contribute to the development...... of foot ulcers in diabetic patients....

  8. Influence of repetitive mechanical loading on MMP2 activity in tendon fibroblasts.

    Science.gov (United States)

    Huisman, Elise; Lu, Alex; Jamil, Sarwat; Mousavizadeh, Rouhollah; McCormack, Robert; Roberts, Clive; Scott, Alex

    2016-11-01

    Matrix metalloproteinase2 has been implicated in tendon pathology caused by repetitive movements. However, its activity in the early stages of the tendon's response to overuse, and its presence in the circulation as a possible indicator of tendon degradation, remain unknown. Human tendon cells were repetitively stretched for 5 days, and the rabbit Achilles tendon complex underwent repetitive motion 3× per week for 2 weeks. Quantitative polymer chain reaction analysis was performed to detect matrix metalloproteinase2/14 and tissue inhibitor of matrix metalloproteinase2 messenger ribonucleic acid of cells and rabbit tissue, and matrix metalloproteinase2 protein levels were determined with an enzyme linked immunoassay. Matrix metalloproteinase2 activity was examined using zymography of the conditioned media, tendon and serum. Immunohistochemistry was used to localize matrix metalloproteinase2 in tendon tissue, and the density of fibrillar collagen in tendons was examined using second harmonic generation microscopy. Tendon cells stretched with high strain or high frequency demonstrated increased matrix metalloproteinase2 messenger ribonucleic acid and protein levels. Matrix metalloproteinase2 activity was increased in the rabbit Achilles tendon tissue at weeks 1 and 2; however, serum activity was only increased at week 1. After 2 weeks of exercise, the collagen density was lower in specific regions of the exercised rabbit Achilles tendon complex. Matrix metalloproteinase2 expression in exercised rabbit Achilles tendons was detected surrounding tendon fibroblasts. Repetitive mechanical stimulation of tendon cells results in a small increase in matrix metalloproteinase2 levels, but it appears unlikely that serum matrix metalloproteinase2 will be a useful indicator of tendon overuse injury. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1991-2000, 2016. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Tendinopathy of the long head of the biceps tendon: histopathologic analysis of the extra-articular biceps tendon and tenosynovium

    Directory of Open Access Journals (Sweden)

    Streit JJ

    2015-03-01

    Full Text Available Jonathan J Streit,1 Yousef Shishani,1 Mark Rodgers,2 Reuben Gobezie1 1The Cleveland Shoulder Institute, 2Department of Pathology, University Hospitals of Cleveland, Cleveland, OH, USA Background: Bicipital tendinitis is a common cause of anterior shoulder pain, but there is no evidence that acute inflammation of the extra-articular long head of the biceps (LHB tendon is the root cause of this condition. We evaluated the histologic findings of the extra-articular portion of the LHB tendon and synovial sheath in order to compare those findings to known histologic changes seen in other tendinopathies. Methods: Twenty-six consecutive patients (mean age 45.4±13.7 years underwent an open subpectoral biceps tenodesis for anterior shoulder pain localized to the bicipital groove. Excised tendons were sent for histologic analysis. Specimens were graded using a semiquantitative scoring system to evaluate tenocyte morphology, the presence of ground substance, collagen bundle characteristics, and vascular changes. Results: Chronic inflammation was noted in only two of 26 specimens, and no specimen demonstrated acute inflammation. Tenocyte enlargement and proliferation, characterized by increased roundness and size of the cell and nucleus with proteoglycan matrix expansion and myxoid degenerative changes, was found in all 26 specimens. Abundant ground substance, collagen bundle changes, and increased vascularization were visualized in all samples. Conclusion: Anterior shoulder pain attributed to the biceps tendon does not appear to be due to an inflammatory process in most cases. The histologic findings of the extra-articular portion of the LHB tendon and synovial sheath are similar to the pathologic findings in de Quervain tenosynovitis at the wrist, and may be due to a chronic degenerative process similar to this and other tendinopathies of the body. Keywords: biceps tendinitis, biceps tendinopathy, tenosynovium, anterior shoulder pain, long head biceps

  10. Exposure to buffer solution alters tendon hydration and mechanics.

    Science.gov (United States)

    Safa, Babak N; Meadows, Kyle D; Szczesny, Spencer E; Elliott, Dawn M

    2017-08-16

    A buffer solution is often used to maintain tissue hydration during mechanical testing. The most commonly used buffer solution is a physiological concentration of phosphate buffered saline (PBS); however, PBS increases the tissue's water content and decreases its tensile stiffness. In addition, solutes from the buffer can diffuse into the tissue and interact with its structure and mechanics. These bathing solution effects can confound the outcome and interpretation of mechanical tests. Potential bathing solution artifacts, including solute diffusion, and their effect on mechanical properties, are not well understood. The objective of this study was to measure the effects of long-term exposure of rat tail tendon fascicles to several concentrations (0.9-25%) of NaCl, sucrose, polyethylene glycol (PEG), and SPEG (NaCl+PEG) solutions on water content, solute diffusion, and mechanical properties. We found that with an increase in solute concentration the apparent water content decreased for all solution types. Solutes diffused into the tissue for NaCl and sucrose, however, no solute diffusion was observed for PEG or SPEG. The mechanical properties changed for both NaCl solutions, in particular after long-term (8h) incubation the modulus and equilibrium stress decreased compared to short-term (15min) for 25% NaCl, and the cross sectional area increased for 0.9% NaCl. However, the mechanical properties were unchanged for both PEG and SPEG except for minor alterations in stress relaxation parameters. This study shows that NaCl and sucrose buffer solutions are not suitable for long-term mechanical tests. We therefore propose using PEG or SPEG as alternative buffer solutions that after long-term incubation can maintain tissue hydration without solute diffusion and produce a consistent mechanical response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Tendon Reattachment to Bone in an Ovine Tendon Defect Model of Retraction Using Allogenic and Xenogenic Demineralised Bone Matrix Incorporated with Mesenchymal Stem Cells.

    Directory of Open Access Journals (Sweden)

    Tanujan Thangarajah

    Full Text Available Tendon-bone healing following rotator cuff repairs is mainly impaired by poor tissue quality. Demineralised bone matrix promotes healing of the tendon-bone interface but its role in the treatment of tendon tears with retraction has not been investigated. We hypothesized that cortical demineralised bone matrix used with minimally manipulated mesenchymal stem cells will result in improved function and restoration of the tendon-bone interface with no difference between xenogenic and allogenic scaffolds.In an ovine model, the patellar tendon was detached from the tibial tuberosity and a complete distal tendon transverse defect measuring 1 cm was created. Suture anchors were used to reattach the tendon and xenogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5, or allogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5 were used to bridge the defect. Graft incorporation into the tendon and its effect on regeneration of the enthesis was assessed using histomorphometry. Force plate analysis was used to assess functional recovery.Compared to the xenograft, the allograft was associated with significantly higher functional weight bearing at 6 (P = 0.047, 9 (P = 0.028, and 12 weeks (P = 0.009. In the allogenic group this was accompanied by greater remodeling of the demineralised bone matrix into tendon-like tissue in the region of the defect (p = 0.015, and a more direct type of enthesis characterized by significantly more fibrocartilage (p = 0.039. No failures of tendon-bone healing were noted in either group.Demineralised bone matrix used with minimally manipulated mesenchymal stem cells promotes healing of the tendon-bone interface in an ovine model of acute tendon retraction, with superior mechanical and histological results associated with use of an allograft.

  12. The Prevalence and Role of Low Lying Peroneus Brevis Muscle Belly in Patients with Peroneal Tendon Pathologies: A Potential Source for Tendon Subluxation

    OpenAIRE

    Mirmiran, Roya; Squire, Chad; Wassell, Daniel

    2015-01-01

    A low lying peroneus brevis muscle belly is a rare anomaly. There are few published studies that support presence of this anomaly as an etiology for peroneal tendon tear. However, the association between a low lying peroneus muscle belly (LLMB) and tendon subluxation is not well explored. In this retrospective study, the magnetic resonance imaging (MRI) and intraoperative findings of 50 consecutive patients undergoing a primary peroneal tendon surgery, in a five year period, were assessed. Th...

  13. Complex Anatomic Abnormalities of the Lower Leg Muscles and Tendons Associated With Phocomelia: A Case Report.

    Science.gov (United States)

    Hodo, Thomas; Hamrick, Mark; Melenevsky, Yulia

    Musculoskeletal anatomy is widely known to have components that stray from the norm in the form of variant muscle and tendon presence, absence, origin, insertion, and bifurcation. Although these variant muscles and tendons might be deemed incidental and insignificant findings by most, they can be important contributors to pathologic physiology or, more importantly, an option for effective treatment. In the present case report, we describe a patient with phocomelia and Müllerian abnormalities secondary to in utero thalidomide exposure. The patient had experienced recurrent bilateral foot pain accompanied by numbness, stiffness, swelling, and longstanding pes planus. These symptoms persisted despite conservative treatment with orthotics, steroids, and nonsteroidal anti-inflammatory drugs. Radiographic imaging showed dysmorphic and degenerative changes of the ankle and foot joints. Further investigation with magnetic resonance imaging revealed complex anatomic abnormalities, including the absence of the posterior tibialis and peroneus brevis, lateralization of the peroneus longus, and the presence of a variant anterior compartment muscle. The variant structure was likely a previously described anterior compartment variant, anterior fibulocalcaneus, and might have been a source of the recurrent pain. Also, the absence of the posterior tibialis might have caused the pes planus in the present patient, considering that posterior tibialis tendon dysfunction is the most common cause of acquired pes planus. Although thalidomide infrequently affects the lower extremities, its effects on growth and development were likely the cause of this rare array of anatomic abnormalities and resulting ankle and foot pathologic features. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  14. DNA fragmentation and nuclear phenotype in tendons exposed to low-intensity infrared laser

    Science.gov (United States)

    de Paoli, Flavia; Ramos Cerqueira, Larissa; Martins Ramos, Mayara; Campos, Vera M.; Ferreira-Machado, Samara C.; Geller, Mauro; de Souza da Fonseca, Adenilson

    2015-03-01

    Clinical protocols are recommended in device guidelines outlined for treating many diseases on empirical basis. However, effects of low-intensity infrared lasers at fluences used in clinical protocols on DNA are controversial. Excitation of endogenous chromophores in tissues and free radicals generation could be described as a consequence of laser used. DNA lesions induced by free radicals cause changes in DNA structure, chromatin organization, ploidy degrees and cell death. In this work, we investigated whether low-intensity infrared laser therapy could alter the fibroblasts nuclei characteristics and induce DNA fragmentation. Tendons of Wistar rats were exposed to low-intensity infrared laser (830 nm), at different fluences (1, 5 and 10 J/cm2), in continuous wave (power output of 10mW, power density of 79.6 mW/cm2). Different frequencies were analyzed for the higher fluence (10 J/cm2), at pulsed emission mode (2.5, 250 and 2500 Hz), with the laser source at surface of skin. Geometric, densitometric and textural parameters obtained for Feulgen-stained nuclei by image analysis were used to define nuclear phenotypes. Significant differences were observed on the nuclear phenotype of tendons after exposure to laser, as well as, high cell death percentages was observed for all fluences and frequencies analyzed here, exception 1 J/cm2 fluence. Our results indicate that low-intensity infrared laser can alter geometric, densitometric and textural parameters in tendon fibroblasts nuclei. Laser can also induce DNA fragmentation, chromatin lost and consequently cell death, using fluences, frequencies and emission modes took out from clinical protocols.

  15. The Improvement of Bone-Tendon Fixation by Porous Titanium Interference Screw: A Rabbit Animal Model.

    Science.gov (United States)

    Tsai, Pei-I; Chen, Chih-Yu; Huang, Shu-Wei; Yang, Kuo-Yi; Lin, Tzu-Hung; Chen, San-Yuan; Sun, Jui-Sheng

    2018-05-04

    The interference screw is a widely used fixation device in the anterior cruciate ligament (ACL) reconstruction surgeries. Despite the generally satisfactory results, problems of using interference screws were reported. By using additive manufacturing (AM) technology, we developed an innovative titanium alloy (Ti 6 Al 4 V) interference screw with rough surface and inter-connected porous structure designs to improve the bone-tendon fixation. An innovative Ti 6 Al 4 V interference screws were manufactured by AM technology. In vitro mechanical tests were performed to validate its mechanical properties. Twenty-seven New Zealand white rabbits were randomly divided into control and AM screw groups for biomechanical analyses and histological analysis at 4, 8 and 12 weeks postoperatively; while micro-CT analysis was performed at 12 weeks postoperatively. The biomechanical tests showed that the ultimate failure load in the AM interference screw group was significantly higher than that in the control group at all tested periods. These results were also compatible with the findings of micro-CT and histological analyses. In micro-CT analysis, the bone-screw gap was larger in the control group; while for the additive manufactured screw, the screw and bone growth was in close contact. In histological study, the bone-screw gaps were wider in the control group and were almost invisible in the AM screw group. The innovative AM interference screws with surface roughness and inter-connected porous architectures demonstrated better bone-tendon-implant integration, and resulted in stronger biomechanical characteristics when compared to traditional screws. These advantages can be transferred to future interference screw designs to improve their clinical performance. The AM interference screw could improve graft fixation and eventually result in better biomechanical performance of the bone-tendon-screw construct. The innovative AM interference screws can be transferred to future

  16. Cross-cultural adaptation and validation of Persian Achilles tendon Total Rupture Score.

    Science.gov (United States)

    Ansari, Noureddin Nakhostin; Naghdi, Soofia; Hasanvand, Sahar; Fakhari, Zahra; Kordi, Ramin; Nilsson-Helander, Katarina

    2016-04-01

    To cross-culturally adapt the Achilles tendon Total Rupture Score (ATRS) to Persian language and to preliminary evaluate the reliability and validity of a Persian ATRS. A cross-sectional and prospective cohort study was conducted to translate and cross-culturally adapt the ATRS to Persian language (ATRS-Persian) following steps described in guidelines. Thirty patients with total Achilles tendon rupture and 30 healthy subjects participated in this study. Psychometric properties of floor/ceiling effects (responsiveness), internal consistency reliability, test-retest reliability, standard error of measurement (SEM), smallest detectable change (SDC), construct validity, and discriminant validity were tested. Factor analysis was performed to determine the ATRS-Persian structure. There were no floor or ceiling effects that indicate the content and responsiveness of ATRS-Persian. Internal consistency was high (Cronbach's α 0.95). Item-total correlations exceeded acceptable standard of 0.3 for the all items (0.58-0.95). The test-retest reliability was excellent [(ICC)agreement 0.98]. SEM and SDC were 3.57 and 9.9, respectively. Construct validity was supported by a significant correlation between the ATRS-Persian total score and the Persian Foot and Ankle Outcome Score (PFAOS) total score and PFAOS subscales (r = 0.55-0.83). The ATRS-Persian significantly discriminated between patients and healthy subjects. Explanatory factor analysis revealed 1 component. The ATRS was cross-culturally adapted to Persian and demonstrated to be a reliable and valid instrument to measure functional outcomes in Persian patients with Achilles tendon rupture. II.

  17. Fluid Signal Intensity That Mimicked A Supraspinatus Tendon Tear In A Subacromial Injected Shoulder: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hun; Kim, Tae Eun; Shin, Hyun Woong [Daegu Fatima Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Subacromial steroid injections are a common procedure for treating shoulder pain. Several studies have reported on the difficulty of performing an accurate injection into the subacromial bursa, as well as the injected material infiltrated into other regional structures even when an accurate injection was done into the subacromial space. These misplacements, and especially in the rotator cuff, creates high signal intensity on T2WI that can mimic a rotator cuff tear. Bergman and Fredericson found that the bursal and extrabursal fluid is resolved or decreased 3 days after the injection, so they recommended a 3-day delay after the shoulder injection before performing MRI to prevent misinterpretation of the signal changes. We report here on a case of a false fullthickness tear of the supraspinatus tendon on MRI one month after subacromial injection, and the supraspinatus tendon turned out to be intact on the follow up ultrasonography and arthroscopic examination

  18. Healing of the Achilles tendon in rabbits--evaluation by magnetic resonance imaging and histopathology.

    Science.gov (United States)

    Tavares, Wilson Campos; de Castro, Ubiratam Brum; Paulino, Eduardo; Vasconcellos, Leonardo de Souza; Madureira, Ana Paula; Magalhães, Maria Angélica Baron; Mendes, Daniel Victor Moreira; Kakehasi, Adriana Maria; Resende, Vivian

    2014-12-12

    Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) could provide valuable findings for tendon regeneration. A non-invasive image method that can effectively evaluate the quality of the scar tissue has not yet been employed. Thirteen New Zealand rabbits were divided into two groups: group 1--non-treated control (n = 4); group 2--surgical intervention (n = 9). The central portion of the Achilles tendon was resected, and after 30 days, DCE-MRI was performed. Contrast enhancement methods were applied using the region of interest (ROI) technique. In the medium third of the Achilles tendon, the intra-substantial signal intensity and the presence of hyper-intense intra-tendon focus points and of signal heterogeneity were evaluated. Antero-posterior and transversal diameters of the tendon were measured. The Achilles tendon was removed and dissected free from other tissues. Sections from the central part of the tendon were stained for histological analysis. The difference between the contrast enhancement curves of the control and surgical groups (p tendon sheath, which presented irregular contours and intense contrast enhancement. On histology, the Achilles tendon presented diffuse widening of the tendon sheath and wedge-shaped areas with scarring tissue rich in disordered collagen fibres. These findings were related to alteration in the intra-substantial signal intensity, with hyper-signal focus points in the DCE-MRI. MRI with perfusion could be a useful technique for evaluating tissue and fibrous scarring in tendons.

  19. The prevalence of tenosynovitis of the interosseous tendons of the hand in patients with rheumatoid arthritis

    Energy Technology Data Exchange (ETDEWEB)

    Rowbotham, Emma L. [Leeds Teaching Hospitals NHS Trust, Musculoskeletal Radiology Department, Leeds (United Kingdom); Freeston, Jane E. [Department of Rheumatology, Leeds Teaching Hospitals NHS Trust, Leeds (United Kingdom); Emery, Paul [University of Leeds, Arthritis Research UK, Leeds Musculoskeletal Biomedical Research Unit, LTHT Leeds Institute of Rheumatic Musculoskeletal Medicine, Leeds (United Kingdom); Grainger, Andrew J. [Leeds Teaching Hospitals NHS Trust, Musculoskeletal Radiology Department, Leeds (United Kingdom); Chapel Allerton Hospital, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds (United Kingdom)

    2016-02-15

    The aim of this study was to establish the prevalence of tenosynovitis affecting the interosseous tendons of the hand in a rheumatoid arthritis (RA) population and to assess for association with metacarpophalangeal (MCP) joint synovitis, flexor tendon tenosynovitis or ulnar drift. Forty-four patients with RA underwent hand MRI along with 20 normal controls. Coronal 3D T1 VIBE sequences pre- and post-contrast were performed and reconstructed. The presence of interosseous tendon tenosynovitis was recorded alongside MCP joint synovitis, flexor tendon tenosynovitis and ulnar drift. Twenty-one (47.7 %) patients with RA showed interosseous tendon tenosynovitis. Fifty-two (14.8 %) interosseous tendons showed tenosynovitis amongst the RA patients. Interosseous tendon tenosynovitis was more commonly seen in association with adjacent MCP joint synovitis (p < 0.001), but nine MCP joints (5.1 %) showed adjacent interosseous tenosynovitis in the absence of joint synovitis. Interosseous tendon tenosynovitis was more frequently seen in fingers which also showed flexor tendon tenosynovitis (p < 0.001) and in patients with ulnar drift of the fingers (p = 0.01). Tenosynovitis of the hand interosseous tendons was found in 47.7 % of patients with RA. In the majority of cases this was adjacent to MCP joint synovitis; however, interosseous tendon tenosynovitis was also seen in isolation. (orig.)

  20. The prevalence of tenosynovitis of the interosseous tendons of the hand in patients with rheumatoid arthritis

    International Nuclear Information System (INIS)

    Rowbotham, Emma L.; Freeston, Jane E.; Emery, Paul; Grainger, Andrew J.

    2016-01-01

    The aim of this study was to establish the prevalence of tenosynovitis affecting the interosseous tendons of the hand in a rheumatoid arthritis (RA) population and to assess for association with metacarpophalangeal (MCP) joint synovitis, flexor tendon tenosynovitis or ulnar drift. Forty-four patients with RA underwent hand MRI along with 20 normal controls. Coronal 3D T1 VIBE sequences pre- and post-contrast were performed and reconstructed. The presence of interosseous tendon tenosynovitis was recorded alongside MCP joint synovitis, flexor tendon tenosynovitis and ulnar drift. Twenty-one (47.7 %) patients with RA showed interosseous tendon tenosynovitis. Fifty-two (14.8 %) interosseous tendons showed tenosynovitis amongst the RA patients. Interosseous tendon tenosynovitis was more commonly seen in association with adjacent MCP joint synovitis (p < 0.001), but nine MCP joints (5.1 %) showed adjacent interosseous tenosynovitis in the absence of joint synovitis. Interosseous tendon tenosynovitis was more frequently seen in fingers which also showed flexor tendon tenosynovitis (p < 0.001) and in patients with ulnar drift of the fingers (p = 0.01). Tenosynovitis of the hand interosseous tendons was found in 47.7 % of patients with RA. In the majority of cases this was adjacent to MCP joint synovitis; however, interosseous tendon tenosynovitis was also seen in isolation. (orig.)

  1. Presence of a long accessory flexor tendon of the toes in surgical treatment for tendinopathy of the insertion of the calcaneal tendon: case report

    Directory of Open Access Journals (Sweden)

    Nelson Pelozo Gomes Júnior

    2016-02-01

    Full Text Available ABSTRACT The presence of accessory tendons in the foot and ankle needs to be recognized, given that depending on their location, they may cause disorders relating either to pain processes or to handling of the surgical findings. We describe the presence of an accessory flexor tendon of the toes, seen in surgical exposure for transferring the long flexor tendon of the hallux to the calcaneus, due to the presence of a disorder of tendinopathy of the insertion of the calcaneal tendon in association with Haglund's syndrome.

  2. The effect of acute exercise on collagen turnover in human tendons

    DEFF Research Database (Denmark)

    Mørch, Lina Steinrud; Pingel, Jessica; Boesen, Mikael

    2013-01-01

    Mechanical loading of human tendon stimulates collagen synthesis, but the relationship between acute loading responses and training status of the tendon is not clear. We tested the effect of prolonged load deprivation on the acute loading-induced collagen turnover in human tendons, by applying...... the contra-lateral leg was used habitually. Following the procedure both Achilles tendons and calf muscles were loaded with the same absolute load during a 1-h treadmill run. Tissue collagen turnover was measured by microdialysis performed post-immobilization but pre-exercise around both Achilles tendons...... and compared to values obtained by 72-h post-exercise. Power Doppler was used to monitor alterations in intratendinous blood flow velocity of the Achilles tendon and MRI used to quantitate changes in tendon cross-section area. Acute loading resulted in an increased collagen synthesis 72 h after the run in both...

  3. Foot Posture and Patellar Tendon Pain Among Adult Volleyball Players

    NARCIS (Netherlands)

    de Groot, Reinier; Malliaras, Peter; Munteanu, Shannon; Payne, Craig; Morrissey, Dylan; Maffulli, Nicola

    Objective: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. Design: Observational study. Setting: Field-based study among competing athletes. Participants: Volleyball

  4. Mesenchymal stem cells for the treatment of tendon disorders

    Czech Academy of Sciences Publication Activity Database

    Machová-Urdzíková, Lucia; Lesný, Petr; Syková, Eva; Jendelová, Pavla

    2013-01-01

    Roč. 6, 8A (2013), s. 14-23 ISSN 1937-6871 R&D Projects: GA ČR GAP304/10/0326 Institutional support: RVO:68378041 Keywords : Tendinophaty * Mesenchymal Stem Cells * Tendon Rupture Subject RIV: FP - Other Medical Disciplines

  5. Foot posture and patellar tendon pain among adult volleyball players.

    NARCIS (Netherlands)

    Groot, R. de; Malliaras, P.; Munteanu, S.; Payne, C.; Morrissey, D.; Maffulli, N.

    2012-01-01

    OBJECTIVE: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. DESIGN: Observational study. SETTING: Field-based study among competing athletes. PARTICIPANTS: Volleyball

  6. Short Term Results of Arthroscopic Repair of Subscapularis Tendon Tear

    Directory of Open Access Journals (Sweden)

    Zohreh Zafarani

    2009-11-01

    Full Text Available Background:Despite being the largest rotator cuff tendon of the shoulder,the function and clinical relevance of subscapularis pathology has been largely ignored in the literature.Although many studies have focused on subscapularis tears recently,majority of them reported techniques for open repair. The advent of arthroscopy and   arthroscopic repair techniques has opened new frontiers in the diagnosis and repair of torn rotator cuff tendons, including the subscapularis.In this article,we review shortterm results of arthroscopic subscapularis repair. Method: Ten patients with subscapularis tendon tear of the rotator cuff were studied   prospectively including 8 men and 2 women with an average age of 49.7±12.8 years and an average delay in treatment of 23.3 months. Clinical outcomes, including the UCLAscore were assessed in all patients after 3 months of the surgery. Results: 6 patients were followed regularly for more than 6 months,while other 4 patients had a follow-up period of more than a year. The pain score improved from 1.75 to 9 and the UCLA score from 8.8 to 30.6.Conclusions: rthroscopic repair of subscapularis tendon tear results in significant subjective and objective improvement and high levels of patient satisfaction.  

  7. Tuberculosis tenosynovitis of the extensor tendons of the wrist

    OpenAIRE

    Mrabet, Dalila; Ouenniche, Kmar; Mizouni, Habiba; Ounaies, Mouna; Khémiri, Chékib; Sahli, Héla; Sellami, Slaheddine

    2011-01-01

    Mycobacterial tuberculous tenosynovitis of the extensor tendon sheath is an extremely rare manifestation of extrapulmonary tuberculosis. The diagnosis may be easily delayed because of its non-specific clinical signs. We report a new case of tuberculous tenosynovitis of the extensor without concomitant pulmonary tuberculosis or documented immunodeficiency.

  8. Mineralized fibroma of the tendon sheath presenting as a bursitis

    Energy Technology Data Exchange (ETDEWEB)

    Le Corroller, Thomas; Champsaur, Pierre [Hopital Sainte-Marguerite, Service de Radiologie, Marseille (France); Faculte de Medecine de Marseille, Departement d' Anatomie, Marseille (France); Bouvier-Labit, Corinne [Hopital La Timone, Service d' Anatomopathologie, Marseille (France); Sbihi, Abderrahmane [Clinique Juge, Service de Chirurgie orthopedique, Marseille (France)

    2008-12-15

    We report on the clinical, imaging - including ultrasound, computed tomography, and magnetic resonance imaging - and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient. (orig.)

  9. Tubercular tenosynovitis of extensor tendons of foot--a rare ...

    African Journals Online (AJOL)

    Tuberculosis of soft tissues as a result of spread from adjacent bone or joint is a well recognized entity. However isolated tuberculous pyomyositis, bursitis and tenosynovitis are rare, constituting about 1% of skeletal tuberculosis. Tubercular tenosynovitis commonly involves tendon sheaths of wrist and hand. Cases of ...

  10. Mineralized fibroma of the tendon sheath presenting as a bursitis

    International Nuclear Information System (INIS)

    Le Corroller, Thomas; Champsaur, Pierre; Bouvier-Labit, Corinne; Sbihi, Abderrahmane

    2008-01-01

    We report on the clinical, imaging - including ultrasound, computed tomography, and magnetic resonance imaging - and histological features of a fibroma of the tendon sheath with mineralized chondroid and osseous metaplasia, presenting as a semimembranosus bursitis. The anatomical characteristics of the semimembranosus bursa are demonstrated by dissection in a cadaveric specimen and correlated with the imaging findings in our patient. (orig.)

  11. Vibration sensitivity of human muscle spindles and Golgi tendon organs.

    Science.gov (United States)

    Fallon, James B; Macefield, Vaughan G

    2007-07-01

    The responses of the various muscle receptors to vibration are more complicated than a naïve categorization into stretch (muscle spindle primary ending), length (muscle spindle secondary endings), and tension (Golgi tendon organs) receptors. To emphasize the similarity of responses to small length changes, we recorded from 58 individual muscle afferents subserving receptors in the ankle or toe dorsiflexors of awake human subjects (32 primary endings, 20 secondary endings, and six Golgi tendon organs). Transverse sinusoidal vibration was applied to the distal tendon of the receptor-bearing muscle, while subjects either remained completely relaxed or maintained a weak isometric contraction of the appropriate muscle. In relaxed muscle, few units responded in a 1:1 manner to vibration, and there was no evidence of a preferred frequency of activation. In active muscle the response profiles of all three receptor types overlapped, with no significant difference in threshold between receptor types. These results emphasize that when intramuscular tension increases during a voluntary contraction, Golgi tendon organs and muscle spindle secondary endings, not just muscle spindle primary endings, can effectively encode small imposed length changes.

  12. Functional rehabilitation of patients with acute Achilles tendon rupture

    DEFF Research Database (Denmark)

    Mark-Christensen, Troels; Troelsen, Anders; Kallemose, Thomas

    2014-01-01

    PURPOSE: The optimal treatment for acute Achilles tendon rupture (ATR) is continuously debated. Recent studies have proposed that the choice of either operative or non-operative treatment may not be as important as rehabilitation, suggesting that functional rehabilitation should be preferred over...

  13. Patellar Sleeve Fracture With Ossification of the Patellar Tendon.

    Science.gov (United States)

    Damrow, Derek S; Van Valin, Scott E

    2017-03-01

    Patellar sleeve fractures make up greater than 50% of all patellar fractures. They are essentially only seen in the pediatric population because of the thick periosteum and the distal patellar pole apophysis in this group. These fractures can lead to complications if not treated appropriately and in a timely fashion. Complications of missed or untreated patellar sleeve fractures include patella alta, anterior knee pain, and quadriceps atrophy. These can all result in severe limitations in activity. The authors describe a case of a 16-year-old boy who sustained a patellar sleeve fracture 3 years prior to presentation. On presentation, he had patella alta, diminished strength, 5° of extensor lag, and radiographs that revealed bone formation along the patellar tendon. Despite this, he was able to maintain a high level of activity. This case report explores how the patient could have maintained a high level of activity despite having a patellar sleeve fracture. Also, because of the delayed presentation, the patella was ossified and the quadriceps was retracted, which led to a novel approach to reconstructing his distal extensor mechanism. This approach included a V-Y advancement of the quadriceps tendon and patellar tendon reconstruction using the patient's hamstring tendon (semitendinosus). This technique, combined with physical therapy postoperatively, resulted in his return to varsity high school soccer. To the best of the authors' knowledge, this technique has not been reported for this rare condition. [Orthopedics. 2017; 40(2):e357-e359.]. Copyright 2016, SLACK Incorporated.

  14. Avulsion of subscapularis muscle tendon leading to recurrent ...

    African Journals Online (AJOL)

    The dislocation was found to be due to a complete tear of the subscapularis tendon (12 patients) and partial tears in three patients, without fracture of the lesser tuberosity in any of the patients. The repair consisted of mobilisation of the subscapularis muscle and its reinsertion into an osseous trough created in the humerus.

  15. Rehabilitation after surgical treatment of peroneal tendon tears and ruptures

    NARCIS (Netherlands)

    van Dijk, Pim A. D.; Lubberts, Bart; Verheul, Claire; DiGiovanni, Christopher W.; Kerkhoffs, Gino M. M. J.

    2016-01-01

    The purpose of this study was to provide an overview of the available evidence on rehabilitation programmes after operatively treated patients with peroneal tendon tearsand ruptures. A systematic review was performed, and PubMed and EMBASE were searched for relevant studies. Information regarding

  16. Immediate effect of exercise on achilles tendon properties: systematic review.

    Science.gov (United States)

    Obst, Steven J; Barrett, Rod S; Newsham-West, Richard

    2013-08-01

    Understanding the mechanical and morphological adaptation of the Achilles tendon (AT) in response to acute exercise could have important implications for athletic performance, injury prevention, and rehabilitation. The purpose of this study was to conduct a systematic review and critical evaluation of the literature to determine the immediate effect of a single bout of exercise on the mechanical and morphological properties of the AT in vivo. Five electronic research databases were systematically searched for intervention-based studies reporting mechanical and morphological properties of the AT after a single bout of exercise. Searches revealed 3292 possible articles; 21 met the inclusion criteria. There is evidence that maximal isometric contractions and prolonged static stretching (>5 min) of the triceps surae complex cause an immediate decrease in AT stiffness, whereas prolonged running and hopping have minimal effect. Limited but consistent evidence exists, indicating that AT hysteresis is reduced after prolonged static stretching. Consistent evidence supports a reduction in free AT diameter (anterior-posterior) after dynamic ankle exercise, and this change appears most pronounced in the healthy tendon and after eccentric exercise. The mechanical and morphological properties of the AT in vivo are affected by acute exercise in a mode- and dose-dependent manner. Transient changes in AT stiffness, hysteresis, and diameter after unaccustomed exercise modes and doses may expose the tendon to increased risk of strain injury and impact on the mechanical function of the triceps surae muscle-tendon unit.

  17. Finite Element Analysis of the Achilles Tendon While Running

    Directory of Open Access Journals (Sweden)

    Anițaș Răzvan

    2013-02-01

    Full Text Available Introduction: The Achilles tendon is the most frequent recipient of traumatic injuries. The aim of this study is to identify and describe the varying load at ankle level and especially at the Achilles tendon’s insertion on the calcaneus.

  18. The arrangement of muscle fibers and tendons in two muscles used for growth studies.

    Science.gov (United States)

    Stickland, N C

    1983-01-01

    The arrangement of muscle fibres and tendons was examined in the soleus muscle of rats from 6 to 175 days post partum. The muscle was seen to change from a simple structure, with mean fibre length of approximately 90% of complete muscle length, to a unipennate structure, with mean fibre length of only about 60% of muscle length. The dog pectineus muscle was also investigated and found to have a bipennate structure throughout postnatal growth. The arrangement of muscle fibres in both these muscles is such that it might be difficult (particularly in the older animals) to cut a transverse section through all the fibres contained in the muscle; some fibres might not enter the plane of section. Results on muscle fibre number in these muscles at different ages may therefore be misleading.

  19. Heparin functionalization increases retention of TGF-β2 and GDF5 on biphasic silk fibroin scaffolds for tendon/ligament-to-bone tissue engineering.

    Science.gov (United States)

    Font Tellado, Sònia; Chiera, Silvia; Bonani, Walter; Poh, Patrina S P; Migliaresi, Claudio; Motta, Antonella; Balmayor, Elizabeth R; van Griensven, Martijn

    2018-05-01

    The tendon/ligament-to-bone transition (enthesis) is a highly specialized interphase tissue with structural gradients of extracellular matrix composition, collagen molecule alignment and mineralization. These structural features are essential for enthesis function, but are often not regenerated after injury. Tissue engineering is a promising strategy for enthesis repair. Engineering of complex tissue interphases such as the enthesis is likely to require a combination of biophysical, biological and chemical cues to achieve functional tissue regeneration. In this study, we cultured human primary adipose-derived mesenchymal stem cells (AdMCs) on biphasic silk fibroin scaffolds with integrated anisotropic (tendon/ligament-like) and isotropic (bone/cartilage like) pore alignment. We functionalized those scaffolds with heparin and explored their ability to deliver transforming growth factor β2 (TGF-β2) and growth/differentiation factor 5 (GDF5). Heparin functionalization increased the amount of TGF-β2 and GDF5 remaining attached to the scaffold matrix and resulted in biological effects at low growth factor doses. We analyzed the combined impact of pore alignment and growth factors on AdMSCs. TGF-β2 and pore anisotropy synergistically increased the expression of tendon/ligament markers and collagen I protein content. In addition, the combined delivery of TGF-β2 and GDF5 enhanced the expression of cartilage markers and collagen II protein content on substrates with isotropic porosity, whereas enthesis markers were enhanced in areas of mixed anisotropic/isotropic porosity. Altogether, the data obtained in this study improves current understanding on the combined effects of biological and structural cues on stem cell fate and presents a promising strategy for tendon/ligament-to-bone regeneration. Regeneration of the tendon/ligament-to-bone interphase (enthesis) is of significance in the repair of ruptured tendons/ligaments to bone to improve implant integration and

  20. Tendon neuroplastic training reduces tendon pain and muscle inhibition in-season: Changing the way we think about exercise

    NARCIS (Netherlands)

    Rio, E.; Kidgell, D.; Van Ark, M.; Zwerver, J; Sheek, I.; Moseley, G.L.; Gaida, J.; Docking, S.; Cook, J.

    2015-01-01

    Introduction: Patellar tendon pain is at its highest in-season but there are no published data of successful management when athletes are playing and training. Furthermore, there are changes to the cortical control of the quadriceps in patellar tendinopathy (including excess quadriceps inhibition)

  1. Clinical follow-up of horses treated with allogeneic equine mesenchymal stem cells derived from umbilical cord blood for different tendon and ligament disorders.

    Science.gov (United States)

    Van Loon, Vic J F; Scheffer, Carmen J W; Genn, Herman J; Hoogendoorn, Arie C; Greve, Jan W

    2014-01-01

    Mesenchymal stem cells (MSCs) offer promise as therapeutic aids in the repair of tendon and ligament disorders in sport horses. Equine allogeneic MSCs derived from umbilical cord blood (eUCB-MSCs) can be obtained in a minimally invasive fashion with successful propagation of MSCs. The objective of this study was to determine the applicability and therapeutic effect of eUCB-MSCs on tendinitis of the superficial digital flexor tendon, desmitis of the suspensory ligament, tendinitis of the deep digital flexor tendon, and desmitis of the inferior check ligament in clinical cases. A retrospective clinical study was performed. At two equine clinics, 52 warmblood horses were treated with cultured eUCB-MSCs between 2009 and 2012. About 2-10 × 10(6) cells per lesion were administered. When a lesion was treated twice, the total amount could run up to 20 × 10(6) cells. Pearson's chi-squared test was used to compare the effect of the injured structure on the success rate, as well as the effect of the age of the horse. Based on repeated examinations, 40 horses (77%) returned to work on the same or a higher level based on information provided by the owner. Neither the injured structure nor the age of the horse had a statistically significant influence on the result. Overall, the results of treatment of some tendon and ligament injuries with eUCB-MSCs in clinical cases are promising.

  2. Achilles tendon adaptation in cross-country runners across a competitive season.

    Science.gov (United States)

    Stanley, L E; Lucero, A; Mauntel, T C; Kennedy, M; Walker, N; Marshall, S W; Padua, D A; Berkoff, D J

    2018-01-01

    Ultrasound tissue characterization (UTC) is an imaging tool used to quantify tendon structural integrity. UTC has quantified Achilles tendon (AT) acute response to load in athletes; however, AT response to cumulative load over a season is unknown. The purpose of this study was to evaluate AT response across a four-month competitive season in collegiate cross-country (XC) runners. Participants (n=21; male=9, female=12; age=19.8±1.2 years; height=171.9±8.9 cm; weight=60.2±8.5 kg) were imaged using the UTC device with a 10-MHz linear-array transducer mounted in a tracking device. The device captures images at 0.2 mm intervals along the AT. UTC algorithms quantified the stability of pixel brightness over every 17 contiguous transverse images into four echo types (I-IV). A total of 168 scans (n=21, bilateral limbs) were performed monthly across the four-month season (Aug=M1, Sep=M2, Oct=M3, Nov=M4). Echo-type percentages (%) were calculated from each scan. Generalized estimating equations (GEE) linear regression models evaluated echo-type % change (β) over the season (M1=reference). Type I increased from M1 to M4 (β=9.10, Presilience to a competitive season of repetitive loading in highly trained runners. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Effects of training on collagen fibril populations in the suspensory ligament and deep digital flexor tendon of young thoroughbreds.

    Science.gov (United States)

    Patterson-Kane, J C; Firth, E C; Parry, D A; Wilson, A M; Goodship, A E

    1998-01-01

    To determine the effect of a specific galloping exercise regimen on collagen fibril mass-average diameters (MAD) in the deep digital flexor tendon (DDFT) and suspensory ligament (SL) of young Thoroughbreds. 12 Thoroughbred fillies, 21 +/- 1 (mean +/- SD) months old. 6 horses underwent a specific 18-month treadmill training program involving galloping exercise. The remaining 6 horses served as controls, undertaking low-volume walking exercise over the same period. Sections were excised from the midpoint of the DDFT and SL, and small strips were dissected from central and peripheral locations for each structure. Fibril diameters were measured from micrographs of transverse ultrathin sections, using a computerized image analysis program. An MAD value was calculated for the central and peripheral regions of the DDFT and SL for each horse. Values for both regions were compared between exercised and control horses. The MAD did not change significantly with exercise for either the DDFT or the SL. Loading of the DDFT as a result of this exercise regimen was not sufficient to stimulate collagen fibril hypertrophy, in keeping with current data that indicate this tendon, compared with the SL and superficial digital flexor tendon (SDFT), is subjected to low loads. Microtrauma, in terms of reduction in fibril MAD, may have occurred in the SL at a site different from that sampled. Another possibility is that, between the trot and the gallop, loading of the SL does not increase to the same extent as that of the SDFT.

  4. Quadriceps tendon autograft for arthroscopic knee ligament reconstruction: use it now, use it often.

    Science.gov (United States)

    Sheean, Andrew J; Musahl, Volker; Slone, Harris S; Xerogeanes, John W; Milinkovic, Danko; Fink, Christian; Hoser, Christian

    2018-04-28

    Traditional bone-patellar tendon-bone and hamstring tendon ACL grafts are not without limitations. A growing body of anatomic, biomechanical and clinical data has demonstrated the utility of quadriceps tendon autograft in arthroscopic knee ligament reconstruction. The quadriceps tendon autograft provides a robust volume of tissue that can be reliably harvested, mitigating the likelihood of variably sized grafts and obviating the necessity of allograft augmentation. Modern, minimally invasive harvest techniques offer the advantages of low rates of donor site morbidity and residual extensor mechanism strength deficits. New data suggest that quadriceps tendon autograft may possess superior biomechanical characteristics when compared with bone-patella tendon-bone (BPTB) autograft. However, there have been very few direct, prospective comparisons between the clinical outcomes associated with quadriceps tendon autograft and other autograft options (eg, hamstring tendon and bone-patellar tendon-bone). Nevertheless, quadriceps tendon autograft should be one of the primary options in any knee surgeon's armamentarium. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Substitution of porcine small intestinal submucosa for rabbit Achilles tendon, an experimental study.

    Science.gov (United States)

    Gu, Yan; Dai, Kerong

    2002-09-25

    To study the effect of substitution of porcine small intestinal submucosa (SIS) for rabbit Achilles tendon. Porcine SIS was taken out and processed. Part of Achilles tendons of 20 rabbits' right legs were removed and substituted by porcine SIS and the Achilles tendon of the left legs were used as controls. One, four, eight, twelve, and sixteen weeks after the operation 4 rabbits were killed and their right Achilles tendons were taken out to be examined histologically and their maximum load was tested. One week after the operation, the porcine SIS was already fused with the remaining part of rabbit Achilles tendon. Sixteen weeks after all the Achilles tendons looked like normal one. The maximum load of experimental Achilles tendon was 48 N +/- 9 N one week after the operation, and increased gradually. In the 16th week after the operation, the maximum load was 178 N +/- 6 N for the experimental Achilles tendon and 174 N +/- 10 N for the control tendon. The differences of maximum load between different weeks after operation, except that between one week and 4 weeks after, were statistically significant (P Achilles tendon is effective, thus proving the feasibility of in vivo tissue engineering technology.

  6. Treatment of peroneal nerve injuries with simultaneous tendon transfer and nerve exploration.

    Science.gov (United States)

    Ho, Bryant; Khan, Zubair; Switaj, Paul J; Ochenjele, George; Fuchs, Daniel; Dahl, William; Cederna, Paul; Kung, Theodore A; Kadakia, Anish R

    2014-08-06

    Common peroneal nerve palsy leading to foot drop is difficult to manage and has historically been treated with extended bracing with expectant waiting for return of nerve function. Peroneal nerve exploration has traditionally been avoided except in cases of known traumatic or iatrogenic injury, with tendon transfers being performed in a delayed fashion after exhausting conservative treatment. We present a new strategy for management of foot drop with nerve exploration and concomitant tendon transfer. We retrospectively reviewed a series of 12 patients with peroneal nerve palsies that were treated with tendon transfer from 2005 to 2011. Of these patients, seven were treated with simultaneous peroneal nerve exploration and repair at the time of tendon transfer. Patients with both nerve repair and tendon transfer had superior functional results with active dorsiflexion in all patients, compared to dorsiflexion in 40% of patients treated with tendon transfers alone. Additionally, 57% of patients treated with nerve repair and tendon transfer were able to achieve enough function to return to running, compared to 20% in patients with tendon transfer alone. No patient had full return of native motor function resulting in excessive dorsiflexion strength. The results of our limited case series for this rare condition indicate that simultaneous nerve repair and tendon transfer showed no detrimental results and may provide improved function over tendon transfer alone.